Renal function and coronary bypass surgery in patients with ischemic heart failure.

OBJECTIVE: Chronic kidney disease is a known risk factor in cardiovascular disease, but its influence on treatment effect of bypass surgery remains unclear. We assessed the influence of chronic kidney disease on 10-year mortality and cardiovascular outcomes in patients with ischemic heart failure treated with medical therapy (medical treatment) with or without coronary artery bypass grafting. METHODS: We calculated the baseline estimated glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration formula, chronic kidney disease stages 1-5) from 1209 patients randomized to medical treatment or coronary artery bypass grafting in the Surgical Treatment for IsChemic Heart failure trial and assessed its effect on outcome. RESULTS: In the overall Surgical Treatment for IsChemic Heart failure cohort, patients with chronic kidney disease stages 3 to 5 were older than those with stages 1 and 2 (66-71 years vs 54-59 years) and had more comorbidities. Multivariable modeling revealed an inverse association between estimated glomerular filtration rate and risk of death, cardiovascular death, or cardiovascular rehospitalization (all P < .001, but not for stroke, P = .697). Baseline characteristics of the 2 treatment arms were equal for each chronic kidney disease stage. There were significant improvements in death or cardiovascular rehospitalization with coronary artery bypass grafting (stage 1: hazard ratio, 0.71; confidence interval, 0.53-0.96, P = .02; stage 2: hazard ratio, 0.71; confidence interval, 0.59-0.84, P < .0001; stage 3: hazard ratio, 0.76; confidence interval, 0.53-0.96, P = .03). These data were inconclusive in stages 4 and 5 for insufficient patient numbers (N = 28). There was no significant interaction of estimated glomerular filtration rate with the treatment effect of coronary artery bypass grafting (P = .25 for death and P = .54 for death or cardiovascular rehospitalization). CONCLUSIONS: Chronic kidney disease is an independent risk factor for mortality in patients with ischemic heart failure with or without coronary artery bypass grafting. However, mild to moderate chronic kidney disease does not appear to influence long-term treatment effects of coronary artery bypass grafting.

Differential Outcomes With Edetate Disodium-Based Treatment Among Stable Post Anterior vs. Non-Anterior Myocardial Infarction Patients.

BACKGROUND: The Trial to Assess Chelation Therapy (TACT) found that chelation therapy significantly reduced clinical events in patients with a history of myocardial infarction (MI). The initial report of TACT included the observation of an interaction between edetate disodium infusions and MI location, as well as diabetes. Thus, we examined in greater detail the effect of edetate disodium chelation therapy as a function of MI location and diabetes. METHODS: Patients (n = 1708) at least 6 weeks post-MI and age ≥ 50 were randomized to receive 40 infusions of a 500 mL chelation solution or placebo (median follow-up 55 months). The effect of edetate disodium on the primary outcome (all-cause mortality, MI, stroke, hospitalization for angina, or coronary revascularization) was assessed as a function of MI location using log-rank test and Cox regression model, adjusting for other prognostic variables. RESULTS: Among patients with post anterior MI (n = 674), chelation was associated with a lower risk of the primary endpoint (HR 0.63, 95% CI 0.47-0.86, p = 0.003) among anterior MI patients, but not in post non-anterior MI (n = 1034) patients (HR 0.96, 95% CI 0.77-1.20, p = 0.702) (p-for-interaction = 0.032). The point estimates for each component of the primary endpoint favored chelation therapy. The differing treatment effect in patients with post anterior vs. non-anterior MI was consistent among patients with or without diabetes and remained significant after adjusting for other prognostic variables (p < 0.01). CONCLUSIONS: Edetate disodium infusions reduced the risk of cardiovascular events among patients with a prior anterior MI. Future studies should focus on replicating these results and understanding the mechanisms of benefit.

Discordances between predicted and actual risk in obese patients with suspected cardiac ischaemia.

OBJECTIVES: To test the relationship between increasing severity of obesity, calculated risk and observed outcomes. METHODS: Patients with symptoms suggestive of coronary artery disease (CAD) (n=10 003) were stratified according to body mass index (BMI). We compared risk factors, pooled risk scores and physicians' perception of risk. Cox regression tested the association between BMI and (1) presence of obstructive CAD and (2) composite clinical endpoints (death, cardiovascular death, unstable angina hospitalisation and myocardial infarction). RESULTS: BMI was ≥30 kg/m2 in 48% of patients and ≥35 in 20%. Increasingly obese patients were younger, female and non-smoking but with higher prevalence of hypertension, diabetes, black race and sedentary lifestyle. Pooled risk estimates of CAD were highest in those with mid-range BMI. In contrast, physicians' estimation of the likelihood of significant CAD based on clinical impression increased progressively with BMI. For a 10% increase in the Diamond-Forrester probability of CAD, the adjusted OR for obstructive CAD was 1.5 (95% CI 1.4 to 1.5) in patients with BMI <35, but only 1.2 (95% CI 1.1 to 1.3) in those with BMI ≥35 (interaction p<0.001). Framingham Risk Score increased across increasing BMI categories. However, there was a strong and consistent inverse relationship between degree of obesity and all three composite clinical endpoints over a median 25 months of follow-up. CONCLUSIONS: Despite perceptions of higher risk and higher risk scores, increasingly obese patients had obstructive CAD less frequently than predicted and had fewer adverse clinical outcomes. There is a need for risk assessment tools and guidelines that account for obesity. TRIAL REGISTRATION NUMBER: NCT01174550.

CABG Improves Outcomes in Patients With Ischemic Cardiomyopathy: 10-Year Follow-Up of the STICH Trial.

OBJECTIVES: The authors investigated the impact of coronary artery bypass grafting (CABG) on first and recurrent hospitalization in this population. BACKGROUND: In the STICH (Surgical Treatment for Ischemic Heart Failure) trial, CABG reduced all-cause death and hospitalization in patients with and ischemic cardiomyopathy and left ventricular ejection fraction <35%. METHODS: A total of 1,212 patients were randomized (610 to CABG + optimal medical therapy [CABG] and 602 to optimal medical therapy alone [MED] alone) and followed for a median of 9.8 years. All-cause and cause-specific hospitalizations were analyzed as time-to-first-event and as recurrent event analysis. RESULTS: Of the 1,212 patients, 757 died (62.4%) and 732 (60.4%) were hospitalized at least once, for a total of 2,549 total all-cause hospitalizations. Most hospitalizations (66.2%) were for cardiovascular causes, of which approximately one-half (907 or 52.9%) were for heart failure. More than 70% of all hospitalizations (1,817 or 71.3%) were recurrent events. The CABG group experienced fewer all-cause hospitalizations in the time-to-first-event (349 CABG vs. 383 MED, adjusted hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.74 to 0.98; p = 0.03) and in recurrent event analyses (1,199 CABG vs. 1,350 MED, HR: 0.78, 95% CI: 0.65 to 0.94; p < 0.001). This was driven by fewer total cardiovascular (CV) hospitalizations (744 vs. 968; p < 0.001, adjusted HR: 0.66, 95% CI: 0.55 to 0.81; p = 0.001), the majority of which were due to HF (395 vs. 512; p < 0.001, adjusted HR: 0.68, 95% CI: 0.52-0.89; p = 0.005). We did not observe a difference in non-CV events. CONCLUSIONS: CABG reduces all-cause, CV, and HF hospitalizations in time-to-first-event and recurrent event analyses. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).

Myocardial Viability and Long-Term Outcomes in Ischemic Cardiomyopathy.

BACKGROUND: The role of assessment of myocardial viability in identifying patients with ischemic cardiomyopathy who might benefit from surgical revascularization remains controversial. Furthermore, although improvement in left ventricular function is one of the goals of revascularization, its relationship to subsequent outcomes is unclear. METHODS: Among 601 patients who had coronary artery disease that was amenable to coronary-artery bypass grafting (CABG) and who had a left ventricular ejection fraction of 35% or lower, we prospectively assessed myocardial viability using single-photon-emission computed tomography, dobutamine echocardiography, or both. Patients were randomly assigned to undergo CABG and receive medical therapy or to receive medical therapy alone. Left ventricular ejection fraction was measured at baseline and after 4 months of follow-up in 318 patients. The primary end point was death from any cause. The median duration of follow-up was 10.4 years. RESULTS: CABG plus medical therapy was associated with a lower incidence of death from any cause than medical therapy alone (182 deaths among 298 patients in the CABG group vs. 209 deaths among 303 patients in the medical-therapy group; adjusted hazard ratio, 0.73; 95% confidence interval, 0.60 to 0.90). However, no significant interaction was observed between the presence or absence of myocardial viability and the beneficial effect of CABG plus medical therapy over medical therapy alone (P = 0.34 for interaction). An increase in left ventricular ejection fraction was observed only among patients with myocardial viability, irrespective of treatment assignment. There was no association between changes in left ventricular ejection fraction and subsequent death. CONCLUSIONS: The findings of this study do not support the concept that myocardial viability is associated with a long-term benefit of CABG in patients with ischemic cardiomyopathy. The presence of viable myocardium was associated with improvement in left ventricular systolic function, irrespective of treatment, but such improvement was not related to long-term survival. (Funded by the National Institutes of Health; STICH ClinicalTrials.gov number, NCT00023595.).

Predictive Model for High-Risk Coronary Artery Disease.

BACKGROUND: Patients with high-risk coronary artery disease (CAD) may be difficult to identify. METHODS: Using the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) cohort randomized to coronary computed tomographic angiography (n=4589), 2 predictive models were developed for high-risk CAD, defined as left main stenosis (≥50% stenosis) or either (1) ≥50% stenosis [50] or (2) ≥70% stenosis [70] of 3 vessels or 2-vessel CAD involving the proximal left anterior descending artery. Pretest predictors were examined using stepwise logistic regression and assessed for discrimination and calibration. RESULTS: High-risk CAD was identified in 6.6% [50] and 2.4% [70] of patients. Models developed to predict high-risk CAD discriminated well: [50], bias-corrected C statistic=0.73 (95% CI, 0.71-0.76); [70], bias-corrected C statistic=0.73 (95% CI, 0.68-0.77). Variables predictive of CAD in both models included family history of premature CAD, age, male sex, lower glomerular filtration rate, diabetes mellitus, elevated systolic blood pressure, and angina. Additionally, smoking history was predictive of [50] CAD and sedentary lifestyle of [70] CAD. Both models characterized high-risk CAD better than the Pooled Cohort Equation (area under the curve=0.70 and 0.71 for [50] and [70], respectively) and Diamond-Forrester risk scores (area under the curve=0.68 and 0.71, respectively). Both [50] and [70] CAD was associated with more frequent invasive interventions and adverse events than non-high-risk CAD (all P<0.0001). CONCLUSIONS: In contemporary practice, 2.4% to 6.6% of stable, symptomatic patients requiring noninvasive testing have high-risk CAD. A simple combination of pretest clinical variables improves prediction of high-risk CAD over traditional risk assessments. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01174550.

The association between blood pressure and long-term outcomes of patients with ischaemic cardiomyopathy with and without surgical revascularization: an analysis of the STICH trial.

Aims: Hypertension (HTN) is a well-known contributor to cardiovascular disease, including heart failure (HF) and coronary artery disease, and is the leading risk factor for premature death world-wide. A J- or U-shaped relationship has been suggested between blood pressure (BP) and clinical outcomes in different studies. However, there is little information about the significance of BP on the outcomes of patients with coronary artery disease and left ventricular dysfunction. This study aimed to determine the relationship between BP and mortality outcomes in patients with ischaemic cardiomyopathy. Methods and results: The influence of BP during a median follow-up of 9.8 years was studied in a total of 1212 patients with ejection fraction ≤35% and coronary disease amenable to coronary artery bypass grafting (CABG) who were randomized to CABG or medical therapy alone (MED) in the STICH (Surgical Treatment for Ischaemic Heart Failure) trial. Landmark analyses were performed starting at 1, 2, 3, 4, and 5 years after randomization, in which previous systolic BP values were averaged and related to subsequent mortality through the end of follow-up with a median of 9.8 years. Neither a previous history of HTN nor baseline BP had any significant influence on long-term mortality outcomes, nor did they have a significant interaction with MED or CABG treatment. The landmark analyses showed a progressive U-shaped relationship that became strongest at 5 years (χ2 and P-values: 7.08, P = 0.069; 8.72, P = 0.033; 9.86; P = 0.020; 8.31, P = 0.040; 14.52, P = 0.002; at 1, 2, 3, 4, and 5-year landmark analyses, respectively). The relationship between diastolic BP (DBP) and outcomes was similar. The most favourable outcomes were observed in the SBP range 120-130, and DBP 75-85 mmHg, whereas lower and higher BP were associated with worse outcomes. There were no differences in BP-lowering medications between groups. Conclusion: A strong U-shaped relationship between BP and mortality outcomes was evident in ischaemic HF patients. The results imply that the optimal SBP might be in the range 120-130 mmHg after intervention, and possibly be subject to pharmacologic action regarding high BP. Further, low BP was a marker of poor outcomes that might require other interactions and treatment strategies. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Sex Difference in Patients With Ischemic Heart Failure Undergoing Surgical Revascularization: Results From the STICH Trial (Surgical Treatment for Ischemic Heart Failure).

BACKGROUND: Female sex is conventionally considered a risk factor for coronary artery bypass grafting (CABG) and has been included as a poor prognostic factor in multiple cardiac operative risk evaluation scores. We aimed to investigate the association of sex and the long-term benefit of CABG in patients with ischemic left ventricular dysfunction enrolled in the prospective STICH trial (Surgical Treatment for Ischemic Heart Failure Study). METHODS: The STICH trial randomized 1212 patients (148 [12%] women and 1064 [88%] men) with coronary artery disease and left ventricular ejection fraction ≤35% to CABG+medical therapy (MED) versus MED alone. Long-term (10-year) outcomes with each treatment were compared according to sex. RESULTS: At baseline, women were older (63.4 versus 59.3 years; P=0.016) with higher body mass index (27.9 versus 26.7 kg/m2; P=0.001). Women had more coronary artery disease risk factors (diabetes mellitus, 55.4% versus 37.2%; hypertension, 70.9% versus 58.6%; hyperlipidemia, 70.3% versus 58.9%) except for smoking (13.5% versus 21.8%) and had lower rates of prior CABG (0% versus 3.4%; all P<0.05) than men. Moreover, women had higher New York Heart Association class (class III/IV, 66.2% versus 57.0%), lower 6-minute walk capacity (300 versus 350 m), and lower Kansas City Cardiomyopathy Questionnaire overall summary scores (51 versus 63; all P<0.05). Over 10 years of follow-up, all-cause mortality (49.0% versus 65.8%; adjusted hazard ratio, 0.67; 95% confidence interval, 0.52-0.86; P=0.002) and cardiovascular mortality (34.3% versus 52.3%; adjusted hazard ratio, 0.65; 95% confidence interval, 0.48-0.89; P=0.006) were significantly lower in women compared with men. With randomization to CABG+MED versus MED treatment, there was no significant interaction between sex and treatment group in all-cause mortality, cardiovascular mortality, or the composite of all-cause mortality or cardiovascular hospitalization (all P>0.05). In addition, surgical deaths were not statistically different (1.5% versus 5.1%; P=0.187) between sexes among patients randomized to CABG per protocol as initial treatment. CONCLUSIONS: Sex is not associated with the effect of CABG+MED versus MED on all-cause mortality, cardiovascular mortality, the composite of death or cardiovascular hospitalization, or surgical deaths in patients with ischemic left ventricular dysfunction. Thus, sex should not influence treatment decisions about CABG in these patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Impact of Intubation Time on Survival following Coronary Artery Bypass Grafting: Insights from the Surgical Treatment for Ischemic Heart Failure (STICH) Trial.

OBJECTIVE: The authors aimed to assess determinants of intubation time and evaluate its impact on 30-day and 1-year postoperative survival in Surgical Treatment for Ischemic Heart Failure (STICH) trial patients. DESIGN, SETTING, PARTICIPANTS, AND INTERVENTIONS: A multivariable Cox proportional hazards model was used among the 1,446 surgical patients from the STICH trial who survived 36 hours after operation, in order to identify perioperative factors associated with 30-day and 1-year postoperative mortality. A multivariable logistic regression model was used to determine risk factors associated with intubation time. MEASUREMENTS AND MAIN RESULTS: At 36 hours post-operation, 1,298 (out of 1,446) were extubated and 148 (10.2%) still intubated. Median postoperative intubation time was 11.4 hours. Among patients surviving 36 hours, a multivariable model was developed to predict 30-day (c-index = 0.88) and 1-year (c-index = 0.78) mortality. Intubation time was the strongest independent predictor of 30-day (hazard ratio [HR] 5.50) and 1-year mortality (HR 3.69). Predictors of intubation time >36 hours included mitral valve procedure, New York Heart Association class, left ventricular systolic volume index, creatinine, previous coronary artery bypass grafting (CABG), and age. Results were similar in patients surviving 24 hours post-operation, where intubation time was also the strongest predictor of 30-day (HR 4.18, c-index 0.87) and 1-year (HR 2.81, c-index 0.78) mortality. CONCLUSIONS: Intubation time is the strongest predictor of 30-day and 1-year mortality among patients with ischemic heart failure undergoing CABG. Combining intubation time with other mortality risk factors may allow the identification of patients at the highest risk for whom the development of specific strategies may improve outcomes.

The External Validity of Prediction Models for the Diagnosis of Obstructive Coronary Artery Disease in Patients With Stable Chest Pain: Insights From the PROMISE Trial.

OBJECTIVES: This study sought to externally validate prediction models for the presence of obstructive coronary artery disease (CAD). BACKGROUND: A better assessment of the probability of CAD may improve the identification of patients who benefit from noninvasive testing. METHODS: Stable chest pain patients from the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial with computed tomography angiography (CTA) or invasive coronary angiography (ICA) were included. The authors assumed that patients with CTA showing 0% stenosis and a coronary artery calcium (CAC) score of 0 were free of obstructive CAD (≥50% stenosis) on ICA, and they multiply imputed missing ICA results based on clinical variables and CTA results. Predicted CAD probabilities were calculated using published coefficients for 3 models: basic model (age, sex, chest pain type), clinical model (basic model + diabetes, hypertension, dyslipidemia, and smoking), and clinical + CAC score model. The authors assessed discrimination and calibration, and compared published effects with observed predictor effects. RESULTS: In 3,468 patients (1,805 women; mean 60 years of age; 779 [23%] with obstructive CAD on CTA), the models demonstrated moderate-good discrimination, with C-statistics of 0.69 (95% confidence interval [CI]: 0.67 to 0.72), 0.72 (95% CI: 0.69 to 0.74), and 0.86 (95% CI: 0.85 to 0.88) for the basic, clinical, and clinical + CAC score models, respectively. Calibration was satisfactory although typical chest pain and diabetes were less predictive and CAC score was more predictive than was suggested by the models. Among the 31% of patients for whom the clinical model predicted a low (≤10%) probability of CAD, actual prevalence was 7%; among the 48% for whom the clinical + CAC score model predicted a low probability the observed prevalence was 2%. In 2 sensitivity analyses excluding imputed data, similar results were obtained using CTA as the outcome, whereas in those who underwent ICA the models significantly underestimated CAD probability. CONCLUSIONS: Existing clinical prediction models can identify patients with a low probability of obstructive CAD. Obstructive CAD on ICA was imputed for 61% of patients; hence, further validation is necessary.

Impact of Diabetes Mellitus on the Evaluation of Stable Chest Pain Patients: Insights From the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) Trial.

BACKGROUND: The impact of diabetes mellitus on the clinical presentation and noninvasive test (NIT) results among stable outpatients presenting with symptoms suggestive of coronary artery disease (CAD) has not been well described. METHODS AND RESULTS: The PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) trial enrolled 10 003 patients with known diabetic status, of whom 8966 were tested as randomized and had interpretable NIT results (1908 with diabetes mellitus, 21%). Differences in symptoms and NIT results were evaluated using logistic regression. Patients with diabetes mellitus (versus without) were similar in age (median 61 versus 60 years) and sex (female 54% versus 52%), had a greater burden of cardiovascular comorbidities, and had a similar likelihood of nonchest pain symptoms (29% versus 27%). The Diamond-Forrester/Coronary Artery Surgery Study score predicted that patients with diabetes mellitus (versus without) had similar likelihood of obstructive CAD (low 1.8% versus 2.7%; intermediate 92.3% versus 92.6%; high 5.9% versus 4.7%). Physicians estimated patients with diabetes mellitus to have a higher likelihood of obstructive CAD (low to very low: 28.3% versus 40.1%; intermediate 63.9% versus 55.9%; high to very high 7.8% versus 4.0%). Patients with diabetes mellitus (versus without) were more likely to have a positive NIT result (15% versus 11%; adjusted odds ratio, 1.23; P=0.01). CONCLUSIONS: Stable chest pain patients with and without diabetes mellitus have similar presentation and pretest likelihood of obstructive CAD; however, physicians perceive that patients with diabetes mellitus have a higher pretest likelihood of obstructive CAD, an assessment supported by increased risk of a positive NIT. Further evaluation of diabetes mellitus's influence on CAD assessment is required. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01174550.

Quantifying sociodemographic and income disparities in medical therapy and lifestyle among symptomatic patients with suspected coronary artery disease: a cross-sectional study in North America.

OBJECTIVES: To evaluate potential gaps in preventive medical therapy and healthy lifestyle practices among symptomatic patients with suspected coronary artery disease (CAD) seeing primary care physicians and cardiologists and how gaps vary by sociodemographic characteristics and baseline cardiovascular risk. DESIGN: Cross-sectional study assessing potential preventive gaps. PARTICIPANTS: 10 003 symptomatic outpatients evaluated by primary care physicians, cardiologists or other specialists for suspected CAD. SETTING: PROspective Multicenter Imaging Study for Evaluation of Chest Painfrom 2010 to 2014. MEASURES: Primary measures were absence of an antihypertensive, statin or angiotensin-converting enzyme inhibitor/angiotensin receptor blocker for renal protection in patients with hypertension, dyslipidaemia or diabetes, respectively, and being sedentary, smoking or being obese. RESULTS: Preventive treatment gaps affected 14% of patients with hypertension, 36% of patients with dyslipidaemia and 32% of patients with diabetes. Overall, 49% of patients were sedentary, 18% currently smoked and 48% were obese. Women were significantly more likely to not take a statin for dyslipidaemia and to be sedentary. Patients with lower socioeconomic status were also significantly more likely to not take a statin. Compared with Whites, Blacks were significantly more likely to be obese, while Asians were less likely to smoke or be obese. High-risk patients sometimes experienced larger preventive care gaps than low-risk patients. For patients with dyslipidaemia, the presence of a treatment gap was associated with a higher risk of an adverse event (HR 1.35, 95% CI 1.02 to 1.82). CONCLUSIONS: Among contemporary, symptomatic patients with suspected CAD, significant gaps exist in preventive care and lifestyle practices, and high-risk patients sometimes had larger gaps. Differences by sex, age, race/ethnicity, socioeconomic status and geography are modest but contribute to disparities and have implications for improving opulation health. For patients with dyslipidaemia, the presence of a treatment gap was associated with a higher risk of an adverse event. CLINICAL TRIAL REGISTRATION: Clinical Trials.gov identifier NCT01174550.

Safety of coronary CT angiography and functional testing for stable chest pain in the PROMISE trial: A randomized comparison of test complications, incidental findings, and radiation dose.

BACKGROUND: Coronary computed tomography angiography (CTA) and functional testing strategies for stable chest pain yield similar outcomes; one aspect that may guide test choice is safety. METHODS: We compared test safety (test complications, incidental findings, and effective radiation dose) between CTA and functional testing as-tested in PROMISE (PROspective Multicenter Imaging Study for Evaluation of Chest Pain). In the subgroup whose physicians intended nuclear stress over other functional tests if randomized to the functional arm, we compared radiation dose of CTA versus nuclear stress and identified characteristics associated with dose. RESULTS: Of 9470 patients, none had major and <1% had minor complications (CTA: 0.8% [37/4633] vs. functional: 0.6% [27/4837]). CTA identified more incidental findings (11.6% [539/4633] vs. 0.7% [34/4837], p < 0.001), most commonly pulmonary nodules (9.4%, 437/4633). CTA had similar 90-day cumulative radiation dose to functional testing. However, in the subgroup whose physicians intended nuclear stress (CTA 3147; nuclear 3203), CTA had lower median index test (8.8 vs. 12.6 mSv, p < 0.001) and 90-day cumulative (11.6 vs. 13.1 mSv, p < 0.001) dose, independent of patient characteristics. The lowest nuclear doses employed 1-day Tc-99m protocols (12.2 mSv). The lowest CTA doses were at sites performing ≥500 CTAs/year (6.9 mSv) and with advanced (latest available) CT scanners (5.5 mSv). CONCLUSION: Complications were negligibly rare for both CTA and functional testing. CTA detects more incidental findings. Compared to nuclear stress testing, CTA's lower radiation dose, independent of patient characteristics, makes it an attractive test choice. Radiation dose varies with imaging protocol, indicating opportunities to further reduce dose. (ClinicalTrials.gov number, NCT01174550).

Sudden Cardiac Death in Patients With Ischemic Heart Failure Undergoing Coronary Artery Bypass Grafting: Results From the STICH Randomized Clinical Trial (Surgical Treatment for Ischemic Heart Failure).

BACKGROUND: The risk of sudden cardiac death (SCD) in patients with heart failure after coronary artery bypass graft surgery (CABG) has not been examined in a contemporary clinical trial of surgical revascularization. This analysis describes the incidence, timing, and clinical predictors of SCD after CABG. METHODS: Patients enrolled in the STICH trial (Surgical Treatment of Ischemic Heart Failure) who underwent CABG with or without surgical ventricular reconstruction were included. We excluded patients with prior implantable cardioverter-defibrillator and those randomized only to medical therapy. The primary outcome was SCD as adjudicated by a blinded committee. A Cox model was used to examine and identify predictors of SCD. The Fine and Gray method was used to estimate the incidence of SCD accounting for the competing risk of other deaths. RESULTS: Over a median follow-up of 46 months, 113 of 1411 patients who received CABG without (n = 934) or with (n = 477) surgical ventricular reconstruction had SCD; 311 died of other causes. The mean left ventricular ejection fraction at enrollment was 28±9%. The 5-year cumulative incidence of SCD was 8.5%. Patients who had SCD and those who did not die were younger and had fewer comorbid conditions than did those who died of causes other than SCD. In the first 30 days after CABG, SCD (n=5) accounted for 7% of all deaths. The numerically greatest monthly rate of SCD was in the 31- to 90-day time period. In a multivariable analysis including baseline demographics, risk factors, coronary anatomy, and left ventricular function, end-systolic volume index and B-type natriuretic peptide were most strongly associated with SCD. CONCLUSIONS: The monthly risk of SCD shortly after CABG among patients with a low left ventricular ejection fraction is highest between the first and third months, suggesting that risk stratification for SCD should occur early in the postoperative period, particularly in patients with increased preoperative end-systolic volume index or B-type natriuretic peptide. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT0002359.

Identification of Patients With Stable Chest Pain Deriving Minimal Value From Noninvasive Testing: The PROMISE Minimal-Risk Tool, A Secondary Analysis of a Randomized Clinical Trial.

Importance: Guidelines recommend noninvasive testing for patients with stable chest pain, although many subsequently have normal test results and no adverse clinical events. Objective: To describe a risk tool developed to use only pretest clinical data to identify patients with chest pain with normal coronary arteries and no clinical events during follow-up (minimal-risk cohort). Design, Setting, and Participants: This secondary analysis of a randomized, pragmatic comparative effectiveness trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]) includes stable, symptomatic outpatients without known coronary artery disease referred for noninvasive testing at 193 sites in North America. Interventions: Patients were randomized to receive coronary computed tomography angiography (CCTA) vs functional testing. Main Outcomes and Measures: A low-risk tool was developed and internally validated from July 27, 2010, to September 19, 2013, in 4631 patients receiving CCTA as their initial test, with a median follow-up of 25 months. Logistic regression analysis was used to evaluate pretest variables to determine factors associated with minimal risk using a two-thirds random sample for model derivation (n = 3087) and a one-third sample for testing and validation (n = 1544). The model was then applied to the CCTA and functional testing arms, and test results and event rates were ascertained. Results: A total of 1243 of 4631 patients (26.8%) were in the minimal-risk cohort. The final minimal-risk model included 10 clinical variables that together were correlated with normal CCTA results and no clinical events (C statistic = 0.725 for the derivation and validation subsets; 95% CI, 0.705-0.746): younger age; female sex; racial or ethnic minority; no history of hypertension, diabetes, or dyslipidemia; family history of premature coronary artery disease; never smoking; symptoms unrelated to physical or mental stress; and higher high-density lipoprotein cholesterol level. Across the entire PROMISE cohort, this model was associated with the lowest rates of severely abnormal test results (1.3% for CCTA; 5.6% for functional) and cardiovascular death or myocardial infarction (0.5% for a median of 25 months) among patients at the highest probability (10th decile) of minimal risk. Conclusions and Relevance: In contemporary practice, more than 25% of patients with stable chest pain referred for noninvasive testing will have normal coronary arteries and no long-term clinical events. A clinical tool using readily available pretest variables discriminates such minimal-risk patients, for whom deferred testing may be considered. Trial Registration: clinicaltrials.gov Identifier: NCT01174550.

Changes in Medical Therapy and Lifestyle After Anatomical or Functional Testing for Coronary Artery Disease.

BACKGROUND: Diagnostic testing in the care of patients newly presenting with symptoms suggestive of coronary artery disease may influence risk factor management, independent of test type or test results. However, little is known about changes in medications and lifestyle after anatomical or functional testing. METHODS AND RESULTS: We examined what factors influenced preventive medical therapy and lifestyle practices at 60 days among 10 003 symptomatic patients (53% women; mean age 61 years) randomly assigned to anatomical testing with coronary computed tomographic angiography or functional testing (NCT01174550). We also assessed the association of preventive changes with major cardiovascular events. There were no differences in medications/lifestyle at baseline. At 60 days, relative to baseline, the computed tomographic angiography strategy was associated with a higher proportion of patients newly initiating aspirin (11.8% versus 7.8%), statins (12.7% versus 6.2%), and ß-blockers (8.1% versus 5.3%), compared to functional testing (P<0.0001 for each). No significant differences between computed tomographic angiography and functional testing strategies were observed for initiation of exercise, quitting smoking, or weight loss in overweight/obese patients, though overall prevalence of healthy eating was higher after computed tomographic angiography (P=0.002) while obese/overweight status was lower (P=0.040). Positive initial test results and revascularization demonstrated stronger associations with preventive medications and lifestyle than test type. Medication initiation was not associated with fewer cardiovascular events. CONCLUSIONS: Positive initial test results and revascularization are primary drivers of changes in preventive medical and lifestyle practices, with test type making secondary contributions. However, substantial opportunities exist to further reduce cardiovascular risk. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01174550.

Ten-Year Outcomes After Coronary Artery Bypass Grafting According to Age in Patients With Heart Failure and Left Ventricular Systolic Dysfunction: An Analysis of the Extended Follow-Up of the STICH Trial (Surgical Treatment for Ischemic Heart Failure).

BACKGROUND: Advancing age is associated with a greater prevalence of coronary artery disease in heart failure with reduced ejection fraction and with a higher risk of complications after coronary artery bypass grafting (CABG). Whether the efficacy of CABG compared with medical therapy (MED) in patients with heart failure caused by ischemic cardiomyopathy is the same in patients of different ages is unknown. METHODS: A total of 1212 patients (median follow-up, 9.8 years) with ejection fraction ≤35% and coronary disease amenable to CABG were randomized to CABG or MED in the STICH trial (Surgical Treatment for Ischemic Heart Failure). RESULTS: Mean age at trial entry was 60 years; 12% were women; 36% were nonwhite; and the baseline ejection fraction was 28%. For the present analyses, patients were categorized by age quartiles: quartile 1, ≤54 years; quartile, 2 >54 and ≤60 years; quartile 3, >60 and ≤67 years; and quartile 4, >67 years. Older versus younger patients had more comorbidities. All-cause mortality was higher in older compared with younger patients assigned to MED (79% versus 60% for quartiles 4 and 1, respectively; log-rank P=0.005) and CABG (68% versus 48% for quartiles 4 and 1, respectively; log-rank P<0.001). In contrast, cardiovascular mortality was not statistically significantly different across the spectrum of age in the MED group (53% versus 49% for quartiles 4 and 1, respectively; log-rank P=0.388) or CABG group (39% versus 35% for quartiles 4 and 1, respectively; log-rank P=0.103). Cardiovascular deaths accounted for a greater proportion of deaths in the youngest versus oldest quartile (79% versus 62%). The effect of CABG versus MED on all-cause mortality tended to diminish with increasing age (Pinteraction=0.062), whereas the benefit of CABG on cardiovascular mortality was consistent over all ages (Pinteraction=0.307). There was a greater reduction in all-cause mortality or cardiovascular hospitalization with CABG versus MED in younger compared with older patients (Pinteraction=0.004). In the CABG group, cardiopulmonary bypass time or days in intensive care did not differ for older versus younger patients. CONCLUSIONS: CABG added to MED has a more substantial benefit on all-cause mortality and the combination of all-cause mortality and cardiovascular hospitalization in younger compared with older patients. CABG added to MED has a consistent beneficial effect on cardiovascular mortality regardless of age. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Coronary-Artery Bypass Surgery in Patients with Ischemic Cardiomyopathy.

BACKGROUND: The survival benefit of a strategy of coronary-artery bypass grafting (CABG) added to guideline-directed medical therapy, as compared with medical therapy alone, in patients with coronary artery disease, heart failure, and severe left ventricular systolic dysfunction remains unclear. METHODS: From July 2002 to May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to undergo CABG plus medical therapy (CABG group, 610 patients) or medical therapy alone (medical-therapy group, 602 patients). The primary outcome was death from any cause. Major secondary outcomes included death from cardiovascular causes and death from any cause or hospitalization for cardiovascular causes. The median duration of follow-up, including the current extended-follow-up study, was 9.8 years. RESULTS: A primary outcome event occurred in 359 patients (58.9%) in the CABG group and in 398 patients (66.1%) in the medical-therapy group (hazard ratio with CABG vs. medical therapy, 0.84; 95% confidence interval [CI], 0.73 to 0.97; P=0.02 by log-rank test). A total of 247 patients (40.5%) in the CABG group and 297 patients (49.3%) in the medical-therapy group died from cardiovascular causes (hazard ratio, 0.79; 95% CI, 0.66 to 0.93; P=0.006 by log-rank test). Death from any cause or hospitalization for cardiovascular causes occurred in 467 patients (76.6%) in the CABG group and in 524 patients (87.0%) in the medical-therapy group (hazard ratio, 0.72; 95% CI, 0.64 to 0.82; P<0.001 by log-rank test). CONCLUSIONS: In a cohort of patients with ischemic cardiomyopathy, the rates of death from any cause, death from cardiovascular causes, and death from any cause or hospitalization for cardiovascular causes were significantly lower over 10 years among patients who underwent CABG in addition to receiving medical therapy than among those who received medical therapy alone. (Funded by the National Institutes of Health; STICH [and STICHES] ClinicalTrials.gov number, NCT00023595.).

Severity of Remodeling, Myocardial Viability, and Survival in Ischemic LV Dysfunction After Surgical Revascularization.

OBJECTIVES: This study sought to test the hypothesis that end-systolic volume (ESV), as a marker of severity of left ventricular (LV) remodeling, influences the relationship between myocardial viability and survival in patients with coronary artery disease and LV systolic dysfunction. BACKGROUND: Retrospective studies of ischemic LV dysfunction suggest that the severity of LV remodeling determines whether myocardial viability predicts improved survival with surgical compared with medical therapy, with coronary artery bypass grafting (CABG) only benefitting patients with viable myocardium who have smaller ESV. However, this has not been tested prospectively. METHODS: Interactions of end-systolic volume index (ESVI), myocardial viability, and treatment with respect to survival were assessed in patients in the prospective randomized STICH (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease) trial of CABG versus medical therapy who underwent viability assessment (n = 601; age 61 ± 9 years; ejection fraction ≤35%), with a median follow-up of 5.1 years. Median ESVI was 84 ml/m(2). Viability was assessed by single-photon emission computed tomography or dobutamine echocardiography using pre-specified criteria. RESULTS: Mortality was highest among patients with larger ESVI and nonviability (p < 0.001), but no interaction was observed between ESVI, viability status, and treatment assignment (p = 0.491). Specifically, the effect of CABG versus medical therapy in patients with viable myocardium and ESVI ≤84 ml/m(2) (hazard ratio [HR]: 0.85; 95% confidence interval [CI]: 0.56 to 1.29) was no different than in patients with viability and ESVI >84 ml/m(2) (HR: 0.87; 95% CI: 0.57 to 1.31). Other ESVI thresholds yielded similar results, including ESVI ≤60 ml/m(2) (HR: 0.87; 95% CI: 0.44 to 1.74). ESVI and viability assessed as continuous rather than dichotomous variables yielded similar results (p = 0.562). CONCLUSIONS: Among patients with ischemic cardiomyopathy, those with greater LV ESVI and no substantial viability had worse prognosis. However, the effect of CABG relative to medical therapy was not differentially influenced by the combination of these 2 factors. Lower ESVI did not identify patients in whom myocardial viability predicted better outcome with CABG relative to medical therapy. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).

Influence of Baseline Characteristics, Operative Conduct, and Postoperative Course on 30-Day Outcomes of Coronary Artery Bypass Grafting Among Patients With Left Ventricular Dysfunction: Results From the Surgical Treatment for Ischemic Heart Failure (STICH) Trial.

BACKGROUND: Patients with severe left ventricular dysfunction, ischemic heart failure, and coronary artery disease suitable for coronary artery bypass grafting (CABG) are at higher risk for surgical morbidity and mortality. Paradoxically, those patients with the most severe coronary artery disease and ventricular dysfunction who derive the greatest clinical benefit from CABG are also at the greatest operative risk, which makes decision making regarding whether to proceed to surgery difficult in such patients. To better inform such decision making, we analyzed the Surgical Treatment for Ischemic Heart Failure (STICH) CABG population for detailed information on perioperative risk and outcomes. METHODS AND RESULTS: In both STICH trials (hypotheses), 2136 patients with a left ventricular ejection fraction of ≤35% and coronary artery disease were allocated to medical therapy, CABG plus medical therapy, or CABG with surgical ventricular reconstruction. Relationships of baseline characteristics and operative conduct with morbidity and mortality at 30 days were evaluated. There were a total of 1460 patients randomized to and receiving surgery, and 346 (≈25%) of these high-risk patients developed a severe complication within 30 days. Worsening renal insufficiency, cardiac arrest with cardiopulmonary resuscitation, and ventricular arrhythmias were the most frequent complications and those most commonly associated with death. Mortality at 30 days was 5.1% and was generally preceded by a serious complication (65 of 74 deaths). Left ventricular size, renal dysfunction, advanced age, and atrial fibrillation/flutter were significant preoperative predictors of mortality within 30 days. Cardiopulmonary bypass time was the only independent surgical variable predictive of 30-day mortality. CONCLUSIONS: CABG can be performed with relatively low 30-day mortality in patients with left ventricular dysfunction. Serious postoperative complications occurred in nearly 1 in 4 patients and were associated with mortality. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00023595.