Influence of body mass index on the efficacy of revascularization in patients with coronary artery disease.

OBJECTIVE: We examined the effect of body mass index on the association between revascularization strategy and survival in patients with coronary artery disease. METHODS: Using the Duke Database for Cardiovascular Disease, we selected 22,877 patients who underwent cardiac catheterization from January 1986 to August 2004 and were found to have significant coronary artery disease. Patients were categorized into three coronary disease management groups: no revascularization, percutaneous coronary intervention, and coronary artery bypass surgery. Propensity scoring was used to control for coronary artery revascularization strategy. The relationship between body mass index, coronary disease treatment, and survival was assessed via Cox multivariable models adjusting for baseline demographic, clinical, and angiographic characteristics. RESULTS: The median body mass index was 27.2 kg/m(2) (24.4-30.4) in the overall cohort, 27.1 kg/m(2) (24.1-30.3) in the no revacularization group, 27.4 kg/m(2) (24.8-30.9) in the percutaneous intervention group, and 26.9 kg/m(2) (24.4-30.1) in the coronary bypass group. Body mass index was a significant, but weak, predictor of revascularization, with higher indexes predicting lower rates of coronary bypass. Thirty-day survival did not differ across body mass indexes among treatment groups, but survival curves appeared to separate over longer-term follow-up. An inverted U-shaped survival function was noted across all time points after 30 days, with the lowest risk of death at a body mass index of approximately 26 kg/m(2) (independent of revascularization strategy). Coronary bypass was associated with the highest survival at all later time points, whereas no revascularization was associated with the lowest. CONCLUSIONS: Extremes of body mass index are associated with lower long-term survival in patients with significant coronary disease. Revascularization, particularly with coronary bypass, is consistently associated with the best survival across the spectrum of body mass indexes.

Prediction of mortality in patients with coronary artery disease undergoing vasodilator stress testing: a comparison between 99mTc-tetrofosmin and 99mTc-sestamibi.

PURPOSE: To compare the prognostic ability of the imaging agents 99mTc-sestamibi versus 99mTc-tetrofosmin to predict mortality outcomes in patients with documented coronary artery disease and undergoing vasodilator stress testing. MATERIALS AND METHODS: The study included 2147 consecutive patients who underwent rest and stress single photon emission computed tomographic (SPECT) examination with either 99mTc-sestamibi (n=1128) or 99mTc-tetrofosmin (n=1019). Information relating to all-cause death and cardiovascular death was collected over a 4-year study period. Unadjusted Kaplan-Meier estimates were compared for the two imaging agents. Cox proportional hazard models were examined to determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent after adjusting for clinical and demographic characteristics. Additionally, the interaction between SSS and agent was examined to determine if the effect of SSS on prognosis was different for the two agents. RESULTS: Vasodilator agents were used for stress testing in all patients who received 99mTc-tetrofosmin and 99mTc-sestamibi. Despite differences in patient risk factors Kaplan-Meier estimates were similar for the two groups of patients. Resulting P-values for differences between models for the end points of (1) death from any cause and (2) cardiovascular death showed that SSS combined with clinical index was significantly better than a model that adjusted for only baseline characteristics (P<0.0001 for both endpoints). The addition of imaging agent (99mTc-tetrofosmin or 99mTc-sestamibi) to the model containing both SSS and the clinical characteristics did not show further significant improvement (P=0.62, P=0.96 for death from any cause and cardiovascular death, respectively). CONCLUSION: The type of clinically available 99mTc-labelled myocardial perfusion agents did not affect interpretation of results for prognostic assessment.

Mortality risk associated with ejection fraction differs across resting nuclear perfusion findings.

BACKGROUND: Left ventricular ejection fraction (LVEF) is a significant predictor of morbidity and death. The nuclear summed rest score (SRS) measures myocardial perfusion defects and provides prognostic information, but its effects on long-term outcomes are not fully established. Moreover, information regarding the potential interaction between these 2 covariates is limited. The purpose of this study was to determine whether the mortality risk associated with LVEF is the same across all values of SRS in a population undergoing evaluation for ischemic heart disease. METHODS AND RESULTS: We examined 3,187 patients who underwent cardiac catheterization and perfusion single photon emission computed tomography imaging with a maximum follow-up of 8.1 years and median follow-up of 3.1 years. Cox proportional hazards modeling showed that increasing nuclear SRS and decreasing LVEF were independently associated with a higher long-term mortality rate, with a clinically significant interaction between them (P = .032). Patients with a normal LVEF and a high SRS (greater perfusion abnormality) have a prognosis similar to those with a reduced LVEF. CONCLUSIONS: Resting perfusion studies provide prognostic information for long-term survival and significantly impact the interpretation of mortality risk associated with changes in LVEF. Patient prognostication, risk stratification, and future research using these variables should take this interaction into account.

Techniques and benefits of multiple internal mammary artery bypass at 20 years of follow-up.

BACKGROUND: In patients with multivessel coronary artery disease, performing multiple internal mammary artery (MIMA) grafts to two coronary systems during coronary artery bypass grafting (CABG) improves clinical outcome. Few databases have decades of follow-up, however, and the optimal configuration is still in question. The purpose of this study was to assess 20-year clinical benefits of MIMA grafting and to evaluate the possible effects of two different MIMA configurations. METHODS: From 1984 to 1986, 867 patients with multivessel coronary disease underwent CABG. Single (SIMA) IMA grafts were used in 490 and multiple (MIMA) IMA grafts in 377, along with concomitant saphenous veins. Generally, MIMAs were placed to the two largest coronary systems. Among baseline characteristics, only smoking, diabetes, and hypertension were significantly higher for MIMA versus SIMA. Multivariable Cox model analysis was used to assess outcome differences between groups. RESULTS: During a median follow-up of 20 years, the composite of mortality, myocardial infarction, percutaneous coronary intervention, and redo CABG was significantly reduced after MIMA versus SIMA (p = 0.013). Event-free survival was extended by almost 1 year (p = 0.018), and redo CABG was reduced by 59% (p = 0.005). A comparison within the MIMA group was made between 235 patients receiving IMA grafts to left anterior descending/left circumflex territories versus 122 with grafts to left anterior descending/right coronary artery systems. No significant difference in composite outcome was observed between these configurations (p = 0.88). CONCLUSIONS: These data confirm the clinical benefits of MIMA grafting in multivessel coronary disease to 20 years of follow-up. As long as MIMAs are placed to the two largest coronary systems, no significant differences in long-term results are evident between left anterior descending/left circumflex and left anterior descending/right coronary artery configurations.

Clopidogrel use and long-term clinical outcomes after drug-eluting stent implantation.

CONTEXT: Recent studies of drug-eluting intracoronary stents suggest that current antiplatelet regimens may not be sufficient to prevent late stent thrombosis. OBJECTIVE: To assess the association between clopidogrel use and long-term clinical outcomes of patients receiving drug-eluting stents (DES) and bare-metal stents (BMS) for treatment of coronary artery disease. DESIGN, SETTING, AND PATIENTS: An observational study examining consecutive patients receiving intracoronary stents at Duke Heart Center, a tertiary care medical center in Durham, NC, between January 1, 2000, and July 31, 2005, with follow-up contact at 6, 12, and 24 months through September 7, 2006. Study population included 4666 patients undergoing initial percutaneous coronary intervention with BMS (n = 3165) or DES (n = 1501). Landmark analyses were performed among patients who were event-free (no death, myocardial infarction [MI], or revascularization) at 6- and 12-month follow-up. At these points, patients were divided into 4 groups based on stent type and self-reported clopidogrel use: DES with clopidogrel, DES without clopidogrel, BMS with clopidogrel, and BMS without clopidogrel. MAIN OUTCOME MEASURES: Death, nonfatal MI, and the composite of death or MI at 24-month follow-up. RESULTS: Among patients with DES who were event-free at 6 months (637 with and 579 without clopidogrel), clopidogrel use was a significant predictor of lower adjusted rates of death (2.0% with vs 5.3% without; difference, -3.3%; 95% CI, -6.3% to -0.3%; P = .03) and death or MI (3.1% vs 7.2%; difference, -4.1%; 95% CI, -7.6% to -0.6%; P = .02) at 24 months. However, among patients with BMS (417 with and 1976 without clopidogrel), there were no differences in death (3.7% vs 4.5%; difference, -0.7%; 95% CI, -2.9% to 1.4%; P = .50) and death or MI (5.5% vs 6.0%; difference, -0.5%; 95% CI, -3.2% to 2.2%; P = .70). Among patients with DES who were event-free at 12 months (252 with and 276 without clopidogrel), clopidogrel use continued to predict lower rates of death (0% vs 3.5%; difference, -3.5%; 95% CI, -5.9% to -1.1%; P = .004) and death or MI (0% vs 4.5%; difference, -4.5%; 95% CI, -7.1% to -1.9%; P<.001) at 24 months. However, among patients with BMS (346 with and 1644 without clopidogrel), there continued to be no differences in death (3.3% vs 2.7%; difference, 0.6%; 95% CI, -1.5% to 2.8%; P = .57) and death or MI (4.7% vs 3.6%; difference, 1.0%; 95% CI, -1.6% to 3.6%; P = .44). CONCLUSIONS: The extended use of clopidogrel in patients with DES may be associated with a reduced risk for death and death or MI. However, the appropriate duration for clopidogrel administration can only be determined within the context of a large-scale randomized clinical trial.

Temporal trends in target vessel revascularization in clinical practice: long-term outcomes following coronary stenting from the Duke Database for Cardiovascular Disease.

OBJECTIVE: We examined outcomes of clinical restenosis and temporal trends in repeat target vessel revascularization (TVR) among a broad, unselected patient population undergoing percutaneous coronary revascularization. BACKGROUND: The extent to which clinical trials involving protocol-specified follow-up angiography reflect real-world practice where interventions are driven by clinical restenosis is not completely understood. Whether clinical outcomes have varied over a long-term period that has paralleled substantial advances in stent design, balloon delivery catheter and adjunctive pharmacologic therapies is uncertain. METHODS: To characterize the effectiveness of coronary stenting in routine practice, we examined 1-year clinical outcomes of death and repeat TVR among 5,765 patients enrolled in the Duke Database for Cardiovascular Disease who underwent stent placement between 1994 and 2002. To assess for temporal trends in outcomes, patients were further divided into tertiles according to the year of initial revascularization. RESULTS: Overall, the 1-year occurrence of TVR and death was 11.4% and 4.9%, respectively. Rates of repeat TVR increased at 3-month intervals, with most events occurring prior to 9 months. In an adjusted analysis over an 8-year period, 1-year survival did not significantly differ across patient tertiles (p = 0.95), although rates of recurrent TVR significantly decreased (1994-1996, 11.1%; 1997-1999, 11.5%; 2000-2002, 9.3%; p = 0.003). CONCLUSIONS: In a broad patient population in whom repeat angiography is not protocol-specified, most events occur within the initial months following revascularization, yet late clinical restenosis continues. Although survival has not improved since the introduction of coronary stents, overall rates of repeat revascularization have modestly, but significantly, declined.

Selection of surgical or percutaneous coronary intervention provides differential longevity benefit.

BACKGROUND: Treatment of coronary artery disease (CAD) is evolving with better medications, improvements in percutaneous coronary intervention (PCI), and enhanced techniques for coronary artery bypass grafting (CABG). METHODS: In this study, 18,481 patients with significant (>75% stenosis) CAD treated at a single center between 1986 and 2000 were assigned to one of three groups based on initial treatment strategy: medical therapy (MED) (n = 6862), PCI (n = 6292), or CABG (n = 5327). Each group was categorized into 3 groups according to baseline severity of CAD: low-severity (predominantly 1-vessel), intermediate-severity (predominantly 2-vessel), and high-severity (all 3-vessel), and prospectively evaluated in Cox models for all-cause mortality adjusted for cardiac risk, comorbidity, and propensity for selection of a specific treatment. Treatments were compared for the entire period and three eras (1: 1986 to 1990; 2: 1991 to 1995; 3: 1996 to 2000), the last encompassing widespread availability of PCI with stenting. RESULTS: Survival significantly improved in all groups for all degrees of CAD, despite increasing severity of illness. Revascularization strategies provided significant survival over MED with 8.1, 10.6, and 23.6 additional months per 15 years of follow-up for low-severity, intermediate-severity, and high-severity CAD, respectively. Therapeutic improvements led to increased survival of 5.3 additional months per 7 years of follow-up (95% confidence interval, 0.2 to 10.2; p = 0.039) in era 3 for CABG compared with PCI for high-severity CAD. CONCLUSIONS: Initial revascularization strategies result in significant survival advantage over MED for all CAD levels. Patients with high-severity CAD have reduced survival with PCI compared with those initially treated with CABG.

Predicting significant coronary artery disease in patients with left ventricular dysfunction.

BACKGROUND: Because coronary artery disease (CAD) is a prevalent comorbidity in patients with low ejection function (EF), a number of patients with heart failure undergo diagnostic cardiac catheterization. The objective of this study was to develop a model to assist clinicians in determining the likelihood of CAD before cardiac catheterization. METHODS: This study was a retrospective analysis using the Duke Databank for Cardiovascular Disease. From the databank, 2054 patients who underwent cardiac catheterization between 1992 and 2002 that was preceded by echocardiography with an EF of < 45% were identified. The patients' median age was 63 years, and the median EF was 30%. Patients were considered to have significant CAD if any major epicardial vessel had > or = 75% stenosis. A multivariable model of CAD was generated using stepwise logistic regression. We included demographic, clinical, electrocardiographic, and echocardiographic parameters, including segmental wall motion abnormality. RESULTS: Of the patients who met the criteria, 1184 (58%) had significant CAD and 870 (42%) did not. Significant predictors of CAD, in the order of their ability to predict significant CAD, included history of myocardial infarction, age, diabetes mellitus, Q wave on electrocardiogram, male sex, and segmental wall motion abnormality (all P < .0001). The area under the receiver operating characteristic curve was 0.865. CONCLUSIONS: By using baseline demographic and clinical characteristics, we developed a highly discriminatory diagnostic model for predicting CAD in patients with heart failure. Given the high prevalence of patients without CAD in this cohort, accurate baseline assessment of patients with left ventricular dysfunction for CAD might avoid unnecessary invasive procedures.

Comparison of long-term (seven year) outcomes among patients undergoing percutaneous coronary revascularization with versus without stenting.

Coronary stents have markedly improved the short- and intermediate-term safety and efficacy of percutaneous coronary intervention by improving acute gains in luminal dimensions, decreasing abrupt vessel occlusion, and decreasing restenosis, yet the long-term benefit of coronary stenting remains uncertain. We examined long-term clinical outcomes of death, myocardial infarction, and repeat target vessel revascularization (TVR) among patients enrolled in the Duke Database for Cardiovascular Disease who underwent revascularization with percutaneous transluminal coronary angioplasty alone or stent placement from 1990 to 2002. Among 6,956 patients who underwent percutaneous revascularization, propensity modeling was applied to identify 1,288 matched patients with a similar likelihood to receive coronary stents according to clinical, angiographic, and demographic characteristics. Significant (p <0.05) predictors of stent placement included multivessel disease, diabetes, hypertension, recent myocardial infarction, decreased ejection fraction, and year of study entry. At a median follow-up of 7 years, although treatment with coronary stenting was associated with a significant and sustained decrease in repeat TVR (18.0% vs 28.1%, p = 0.0002) and the occurrence of death, myocardial infarction or TVR (39.2% vs 45.8%, p = 0.004), long-term survival did not significantly differ between treatment groups (19.9% vs 20.5%, p = 0.72). Outcomes of death and myocardial infarction did not significantly differ between patients who did and did not undergo repeat TVR. In conclusion, compared with angioplasty alone, revascularization with coronary stents provides a significant early and sustained decrease in the need for repeat revascularization, but stents do not influence long-term survival.

Outcomes by race and etiology of patients with left ventricular systolic dysfunction.

Previous studies have shown that blacks have worse long-term outcomes than whites who have systolic heart failure. The reasons for these racial differences remain unclear. We investigated the effect of race and etiology of heart failure on outcomes of patients who had left ventricular (LV) systolic dysfunction. We studied records of 1,977 patients (27% black) who underwent cardiac catheterization who had New York Heart Association class II to IV symptoms and a LV ejection fraction <40%. Adjusted Cox's proportional hazards regression models were examined for the end points of mortality, rehospitalization, and a composite of the 2. Black versus white patients were younger (median age 56 vs 63 years, p <0.01), more often were women (49% vs 33%, p <0.01), had diabetes (37% vs 31%, p = 0.02), and hypertension (75% vs 56%, p <0.01). Black patients were less likely to have significant coronary artery disease by angiography (41% vs 69%, p <0.01). Race was not an independent predictor of mortality (hazard ratio 1.09, 95% confidence interval 0.93 to 1.28, p = 0.27). After adjusted survival curves were stratified by race and etiology, the estimates indicated that among those patients who had nonischemic LV dysfunction, blacks appeared to have worse survival than whites. Thus, we found no racial differences in the long-term mortality risk of patients who had symptomatic LV systolic dysfunction. In conclusion, after stratifying by ischemic and nonischemic etiologies, we found decreased survival in blacks who had a nonischemic etiology compared with whites. There were no racial differences in rehospitalization between patients who had ischemic LV systolic dysfunction and those who did not.

Patient survival characteristics after routine mitral valve repair for ischemic mitral regurgitation.

BACKGROUND: Ischemic mitral regurgitation has been associated with diminished survival compared with nonischemic mitral regurgitation. Conversion from mitral valve replacement to valve repair has improved prognosis, but it is unclear whether ischemic mitral regurgitation remains an independent predictor of outcome after mitral valve repair. METHODS: Five hundred thirty-five patients undergoing mitral valve repair (primarily rigid ring annuloplasty) with or without coronary bypass from 1993 through 2002 were reviewed retrospectively (ischemic mitral regurgitation, n = 141; nonischemic mitral regurgitation, n = 394). A Cox proportional hazards model evaluated survival as a function of 9 simultaneous covariates: ischemic versus nonischemic mitral regurgitation, age, sex, number of medical comorbidities, ejection fraction, New York Heart Association class, coronary disease, reoperation, and year of operation. RESULTS: According to univariable analysis, patients with ischemic mitral regurgitation had greater age, higher comorbidity, lower ejection fraction, higher New York Heart Association, and higher reoperation rate (all P < .001) compared with those having nonischemic mitral regurgitation. Univariable 30-day mortality was as follows: 4.3% for patients with ischemic mitral regurgitation versus 1.3% for patients with nonischemic mitral regurgitation (P = .01). Unadjusted 5-year mortality was as follows: 44% +/- 5% for patients with ischemic mitral regurgitation versus 16% +/- 3% for patients with nonischemic mitral regurgitation (P < .001). In the multivariable model, however, only the number of preoperative comorbidities and advanced age were independent predictors of survival (P < .0001), whereas ischemic mitral regurgitation, sex, ejection fraction, New York Heart Association class, coronary disease, reoperation, and year of operation did not achieve significance (all P > .19). After being adjusted for differences in all preoperative risk factors, survival was not statistically different between ischemic mitral regurgitation and nonischemic mitral regurgitation (P = .33). CONCLUSIONS: With routine application of rigid ring annuloplasty, long-term patient survival is more influenced by baseline patient characteristics and comorbidity than by ischemic cause of mitral regurgitation per se. Future risk assessment and decision making should be based on patient condition and should not be biased by ischemic cause of mitral regurgitation.

Prediction of death and nonfatal myocardial infarction in high-risk patients: a comparison between the Duke treadmill score, peak exercise radionuclide angiography, and SPECT perfusion imaging.

UNLABELLED: Radionuclide exercise testing provides prognostic information in patients with known or suspected coronary artery disease (CAD). The relative contribution of 3 noninvasive tests--the Duke treadmill score (DTS), first-pass radionuclide angiography with calculation of the ejection fraction (RNA-EF), and perfusion SPECT--has not been comparatively assessed in a high-risk population undergoing all 3 tests. METHODS: We identified 997 patients (75% male; median age, 60 y) who underwent exercise treadmill testing with RNA-EF and SPECT perfusion imaging as a single test. The relative prognostic power of each test was evaluated in both an unadjusted manner and after adjustment for differences in baseline characteristics using Cox proportional hazards models. RESULTS: During a median follow-up of 4.1 y, 175 patients experienced outcome events. Without adjustment for baseline patient characteristics, each of the modalities proved highly predictive of the composite endpoint of cardiovascular death or nonfatal myocardial infarction (MI) (DTS chi(2) = 18.9, P = 0.0001; RNA-EF chi(2) = 34, P = 0.0001; SPECT chi(2) = 11.5, P = 0.0007). In clinically risk-adjusted models, RNA-EF was the most powerful predictor of cardiovascular death compared with the DTS and SPECT (chi(2) = 40.5, 27.6, and 19.8, respectively). Conversely, exercise SPECT perfusion was a stronger predictor of nonfatal MI than the DTS or RNA-EF (chi(2) = 26.7, 15.7, and 16.7, respectively). CONCLUSION: The DTS, perfusion SPECT, and RNA-EF are each significant predictors of cardiovascular events in high-risk patients. The optimal risk stratification of patients for CAD may include all 3 modalities.

Incremental prognostic power of single-photon emission computed tomographic myocardial perfusion imaging in patients with known or suspected coronary artery disease.

Noninvasive stress testing provides prognostic information in patients who have suspected coronary artery disease, but limited data are available on the incremental value of myocardial perfusion testing in high-risk patients. We studied 3,275 patients who underwent cardiac catheterization and single-photon emission computed tomographic (SPECT) perfusion imaging. Median follow-up was 3.1 years for death, cardiovascular death, and a composite of cardiovascular death or nonfatal myocardial infarction. Using Cox's proportional hazards regression models, we examined the relation of SPECT summed stress score (SSS) to each outcome. A 1-unit change in SSS was associated with increased risks of 4%, 7%, and 5% for death, cardiovascular death, and death or nonfatal myocardial infarction, respectively (all p <0.0001). To examine the prognostic utility of SPECT, after baseline adjustments, SSS and angiographic results provided incremental prognostic information for each outcome. Thus, SPECT SSS provides information beyond clinical and angiographic data in patients who have known or suspected coronary artery disease. This information may be useful for stratifying patients into multiple risk categories for future cardiovascular events and potentially guiding therapy.

Single versus multiple internal mammary artery grafting for coronary artery bypass: 15-year follow-up of a clinical practice trial.

BACKGROUND: The long-term clinical advantages of using routine multiple internal mammary artery (IMA) grafts for coronary artery bypass (CAB) are not clear. This study was designed to test the hypothesis that multiple IMA grafts would provide better 15-year outcomes when compared with single IMA and vein grafts. METHODS AND RESULTS: Between 1984 and 1987, 1067 consecutive patients undergoing isolated CAB were referred to 1 surgeon practicing primarily single and another surgeon maximizing multiple IMA grafts (clinical practice trial). A 207-patient subset with multiple IMAs underwent postoperative graft angiography at 1 to 32 weeks to define initial IMA patency. Patients were followed-up yearly, and the groups were analyzed as (I) surgical strategy (surgeon operating) (single=413 versus multiple=654), (II) ultimate operation performed (single=418 versus multiple=449), or (III) single versus multiple coronary systems revascularized with IMAs (single=490 versus multiple=377). Advantages of this study design were that an entire referral population was examined, multiple IMAs were applied to the entire spectrum of baseline patient risk, 15-year follow-up provided a complete prognostic picture, and the subgroups were potentially comparable at baseline. In all 3 analyses, single and multiple groups were statistically similar with respect to baseline, operative, and immediate postoperative variables. Early IMA patency was 98.5% (333/338 grafts patent), validating the quality of IMA procedures. Unadjusted and adjusted 15-year outcome analyses for I, II, and III for death, myocardial infarction, percutaneous coronary intervention, redo coronary bypass, and the composite of all events identified multiple versus single as a significant predictor of outcome for the composite end point in adjusted analysis III (hazard ratio=0.808; 95% CI, 0.689 to 0.948; P=0.009), because of a 5% to 10% absolute reduction in each of the outcome variables at 15 years. Moreover, >50% reduction in reoperation rate was observed at 15 years in every analysis. CONCLUSIONS: At 15-year follow-up, multiple IMA grafting was associated with a 19.2% adjusted risk reduction in death and cardiac events, caused by decreases in all adverse end points and fewer reoperations. These data indicate that the clinical advantages of maximizing IMA conduits are significant. Based on this information, it is suggested that multiple IMA grafting to 2 coronary systems should be applied liberally to patients with noncardiac risk profiles predictive of long-term survival.

Outcome prediction in patients at high risk for coronary artery disease: comparison between 99mTc tetrofosmin and 99mTc sestamibi.

PURPOSE: To determine if there was any difference in the ability of physicians to predict prognosis with technetium 99m ((99m)Tc) sestamibi or (99m)Tc tetrofosmin in a large consecutive series of patients at high risk for coronary artery disease who underwent coronary angiography. MATERIALS AND METHODS: This study included 1,818 consecutive patients who underwent a rest and stress single photon emission computed tomographic (SPECT) examination with either (99m)Tc sestamibi (n = 915) or (99m)Tc tetrofosmin (n = 903) and cardiac catheterization. A clinical index was generated and consisted of clinical and demographic variables. Information concerning death, cardiovascular death, and nonfatal myocardial infarction was 93% complete during the 1.5-year study period. Cox proportional hazards models were generated to help determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent variable to the clinical index. RESULTS: Exercise was used for stress testing in 473 (52%) patients who received (99m)Tc tetrofosmin and 519 (57%) patients who received (99m)Tc sestamibi (P =.06). Cardiovascular death or myocardial infarction occurred in 130 patients. Resulting P values for chi(2) differences between models for the end points of (a) death from any cause, (b) cardiovascular death, and (c) cardiovascular death or myocardial infarction showed that SSS combined with clinical index was a significantly better model than adjusting for only baseline characteristics (P =.001, P <.001, P =.004, respectively). Incremental addition of either (99m)Tc tetrofosmin or (99m)Tc sestamibi to those models containing SSS and the clinical index did not show further significant improvement (P =.87, P =.88, and P =.26 for death from any cause, cardiovascular death, and cardiovascular death or myocardial infarction, respectively). CONCLUSION: This study shows that the type of clinically available (99m)Tc-labeled myocardial perfusion agents should not affect interpretation of results for risk stratification and prognostic assessment.

Several new considerations in mitral valve repair.

BACKGROUND AND AIM OF THE STUDY: A retrospective evaluation was made of a small personal series of patients undergoing mitral valve repair in order to address four contemporary questions: (i) What is the best method of achieving a stable repair in mitral valve prolapse?; (ii) How should patients with pure annular dilatation without prolapse or antecedent ischemia be categorized?; (iii) Are valve procedures in ischemic mitral regurgitation (MR) still associated with less satisfactory early and late outcomes?; and (iv) Is prophylactic amiodarone therapy safe and effective in reducing postoperative arrhythmias? METHODS: Between 1993 and 2002, a total of 118 patients with non-rheumatic MR undergoing isolated mitral valve repair with or without coronary bypass was analyzed retrospectively: of these patients, 66 had prolapse (Group I), 21 had pure annular dilatation (Group II), and 31 had ischemic MR (Group III). All three groups routinely underwent Carpentier ring annuloplasty. Twenty-three patients in Group I were managed with leaflet resection and reconstruction (LRR), but in 1996 the technique for Group I was changed to uniform artificial chordal replacement (ACR) and no leaflet resection (n = 43). Also in 1996, prophylactic amiodarone therapy was first used routinely, and postoperative arrhythmia data were compared to those from prior patients. Baseline and outcome variables were assessed for each group and compared between the three groups. Survival data were evaluated using the Cox proportional hazards model. RESULTS: Significant differences in baseline characteristics were observed: Group II was predominantly female; Group III more often experienced acute presentation; and Groups II and III had more comorbid disorders and left ventricular dysfunction (all p < 0.01). ACR was highly successful for repair of prolapse, and no ACR patient exhibited significant residual MR or outflow tract obstruction. Operative mortality and morbidity were low in all groups, and ischemic etiology failed to be an independent predictor of early or late adverse outcome (p > 0.10). Cox model analysis to nine years of follow up (median 4 years) identified only advanced age and number of comorbidities as influencing late mortality (both p < 0.03). Over the follow up period, 8.7% of LRR patients required reoperation for valve failure due to late chordal rupture, whereas none of the ACR patients failed. Finally, prophylactic amiodarone significantly reduced postoperative arrhythmias (p = 0.03) with no observed complications, and also eliminated death due to arrhythmia. CONCLUSION: Ischemic etiology may be diminishing as an independent risk factor in Group III, at least partially because of uniform valve repair. Group II comprised a distinct entity of females with higher comorbidity, and prophylactic amiodarone therapy seemed useful as a routine measure. Finally, ACR appeared to produce a stable repair in virtually all Group I patients, suggesting that prolapse might be appropriately managed with ring annuloplasty and uniform ACR. However, future studies are suggested for further consideration of these hypotheses.

Chronic kidney disease, mortality, and treatment strategies among patients with clinically significant coronary artery disease.

Cardiovascular disease is an important cause of mortality among patients with chronic kidney disease (CKD). This study describes associations between CKD, cardiac revascularization strategies, and mortality among patients with CKD and cardiovascular disease. All patients undergoing cardiac catheterization at Duke University Medical Center (1995 to 2000) with documented stenosis > or =75% of at least one coronary artery and available creatinine data were included. CKD was staged using creatinine clearance (CrCl) derived from the Cockcroft-Gault formula (normal, > or = 90 ml/min; mild, 60 to 89 ml/min; moderate, 30 to 59 ml/min; severe, 15 to 29 ml/min). Cox proportional-hazard regression estimated the relationship between clinical variables, including CrCl and percutaneous coronary artery intervention (PCI), coronary artery bypass grafting (CABG), medical management, and patient survival. There were 4584 patients included, and 24% had CrCl <60 ml/min. Each 10-ml/min decrement in CrCl was associated with an increase in mortality (hazard ratio, 1.14; P < 0.0001). CABG was associated with a survival benefit among patients with both normal renal function and patients with CKD compared with medical management. In patients with normal renal function, CABG was not associated with survival benefit over PCI. However, in patients with CKD, CABG was associated with improved survival. PCI was associated with a survival benefit compared with medical management among patients with normal, mildly, and moderately impaired renal function. Among patients with severe CKD, PCI was not associated with improved survival. CABG is associated with greater mortality reduction than PCI in severe CKD.

Prognostic significance of elevated troponin I after percutaneous coronary intervention.

OBJECTIVES: We sought to assess the incidence and clinical significance of elevated cardiac troponin I (cTnI) after percutaneous coronary intervention (PCI). BACKGROUND: Elevated creatine kinase-MB (CK-MB) is prognostically important after PCI, but the prognostic significance of elevated cTnI after PCI is uncertain. METHODS: In a prospective substudy of the Sibrafiban Versus Aspirin to Yield Maximum Protection From Ischemic Heart Events Post-acute Coronary Syndromes (SYMPHONY) trials, which randomized patients with acute coronary syndromes (ACS) to receive aspirin or sibrafiban, we measured cTnI (positive, > or =1.5 ng/ml) and CK-MB (positive, > or =7 ng/ml) in 481 patients with PCI. Samples were collected immediately before and at 0, 8 and 16 h after PCI and analyzed by a core laboratory. The primary end point was the Kaplan-Meier estimate of death, myocardial infarction or severe, recurrent ischemia at 90 days. RESULTS: Overall, 230 patients (48%) had elevated cTnI after PCI. Such patients underwent PCI sooner and were more likely to have coronary stenting. Elevated cTnI was associated with nonsignificantly higher risks of the primary end point (11.5% vs. 8.7%; p = 0.15) and of death (1.8% vs. 0.4%; p = 0.4) and a significantly higher risk of death or infarction (10.6% vs. 4.2%; p = 0.005). This pattern was more pronounced for patients who became positive only after PCI: primary end point, 20.7% vs. 10.1% for patients who remained negative after PCI (p = 0.05); death, 5.2% vs. 0% (p = 0.02); death or infarction, 18.1% vs. 4.1% (p = 0.007). CONCLUSIONS: Elevated cTnI, often observed after PCI in patients with ACS, is associated with worse 90-day clinical outcomes. This marker, therefore, is a useful prognostic indicator in such patients.