Seasonal Incidence of Emergent Coronary Artery Bypass Grafting Surgery.

BACKGROUND: Emergent coronary artery bypass grafting (CABG) surgery is often required in the case of severe coronary artery disease, which is refractory to traditional management. The objective of our study was to test the hypothesis that there is seasonal variation in the incidence of emergent CABG. METHODS: A sinusoidal logistic regression model was used to analyze operative data at our cardiovascular institute of 270 cases spanning 5939 calendar days. RESULTS: A cyclic peak risk for emergent CABG was observed for late winter (calendar day 66; P = .036). The odds ratios for the 1-, 2- and 3-month window surrounding this peak were 1.8 (95% CI = 0.94-3.5, P = .072), 1.6 (95% CI = 1.06-2.5, P = .024) and 1.4 (95% CI = 0.9-1.8, P = .066), respectively. CONCLUSION: Our results suggest that a seasonal variation may exist in the incidence of patients presenting with severe coronary artery disease requiring emergent CABG. This information is useful in the scheduling of hospital resources and staff. It also provides important etiology clues underlying coronary artery disease that may lead to future interventions or targeted therapies.

The impact of prior percutaneous coronary intervention on long-term survival after coronary artery bypass grafting.

BACKGROUND: Previous studies examining the influence of prior percutaneous coronary intervention (PCI) on long-term survival after coronary artery bypass grafting (CABG) have reported conflicting results. The purpose of this study was to further examine the influence of prior PCI on long-term survival after CABG at a large tertiary referral heart institute. METHODS: Long-term survival between 1992 and 2011 was compared in non-emergent CABG cases with and without prior PCI. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 2532 (19%) patients had prior PCI before CABG (n=13,354). The median follow-up for study participants was 8.1 years. The median survival for patients with and without prior PCI was 15 years and 14 years, respectively (p<0.0001). Long-term survival was similar between patients with and without prior PCI after adjusting for age, sex, race, hypertension, coronary artery disease severity, congestive heart failure, and prior stroke (adjusted HR=0.99, 95%CI=0.91-1.06). CONCLUSION: Findings from outcomes research are important in the planning of appropriate postoperative patient care. Our study provides additional evidence that prior PCI is not a significant predictor of long-term survival after CABG.

Thromboelastography-Platelet Mapping Allows Safe and Earlier Urgent Coronary Artery Bypass Grafting.

BACKGROUND: The Society of Thoracic Surgeons current (STS) guidelines recommend delaying coronary artery bypass graft surgery (CABG) for several days or performing platelet function testing in stable patients who received P2Y12 inhibitors. Our program routinely uses thromboelastography-platelet mapping (TEG-PM) to expedite CABG in P2Y12 nonresponders. We hypothesize that P2Y12 nonresponders had no difference in length of stay to surgery and blood product transfusion compared with patients undergoing urgent inpatient CABG not treated with a P2Y12 inhibitor. METHODS: A total of 221 patients from 2015 to 2019 were P2Y12 nonresponders based on TEG-PM result of less than 50% adenosine diphosphate inhibition. The control group was 232 consecutive patients who also had urgent inpatient CABG but were not treated preoperatively with a P2Y12 inhibitor. Exclusion criteria were identical between groups. RESULTS: Sixty-seven percent of inpatient CABG patients who were treated preoperatively with a P2Y12 inhibitor were nonresponders. The mean number of days from cardiac surgical consultation to CABG in the TEG-PM nonresponders group was 1.6 ± 0.1 vs 2.1 ± 0.1 in the control group (P < .01). The mean total number of blood product units transfused was 1.6 ± 0.2 in the TEG-PM nonresponders group vs 1.6 ± 0.4 in the control group (P = .91). CONCLUSIONS: Our results demonstrate a very high incidence of P2Y12 nonresponders among patients undergoing urgent CABG at our program. These patients underwent surgery at least 3 days earlier than STS recommendations and common practice with no difference in transfusion requirement. Routine use of TEG-PM to identify P2Y12 nonresponders can safely decrease preoperative hospital length of stay and associated cost and improve resource utilization and patient satisfaction.

Factors Associated with Discharge to a Skilled Nursing Facility after Transcatheter Aortic Valve Replacement Surgery.

An assumption regarding transcatheter aortic valve replacement (TAVR), a minimally invasive procedure for treating aortic stenosis, is that patients remain at, or near baseline and soon return to their presurgical home to resume activities of daily living. However, this does not consistently occur. The purpose of this study was to identify preoperative factors that optimally predict discharge to a skilled nursing facility (SNF) after TAVR. Delineation of these conditions is an important step in developing a risk stratification model to assist in making informed decisions. Data was extracted from the American College of Cardiology (ACC) transcatheter valve therapy (TVT) registry and the Society of Thoracic Surgeons (STS) database on 285 patients discharged from 2012⁻2017 at a tertiary referral heart institute located in the southeastern region of the United States. An analysis of assessment, clinical and demographic variables was used to estimate relative risk (RR) of discharge to a SNF. The majority of participants were female (55%) and white (84%), with a median age of 82 years (interquartile range = 9). Approximately 27% (n = 77) were discharged to a SNF. Age > 75 years (RR = 2.3, p = 0.0026), female (RR = 1.6, p = 0.019), 5-meter walk test (5MWT) >7 s (RR = 2.0, p = 0.0002) and not using home oxygen (RR = 2.9, p = 0.0084) were identified as independent predictive factors for discharge to a SNF. We report a parsimonious risk-stratification model that estimates the probability of being discharged to a SNF following TAVR. Our findings will facilitate making informed treatment decisions regarding this older patient population.

Increased risk of atrial fibrillation among patients undergoing coronary artery bypass graft surgery while receiving nitrates and antiplatelet agents.

Background Postoperative atrial fibrillation (POAF) is a frequent complication of coronary artery bypass graft (CABG) surgery. This arrhythmia occurs more frequently among patients who receive perioperative inotropic therapy (PINOT). Administration of nitrates with antiplatelet agents reduces the conversion rate of cyclic guanosine monophosphate to guanosine monophosphate. This process is associated with increased concentrations of free radicals, catecholamines, and blood plasma volume. We hypothesized that patients undergoing CABG surgery who receive PINOT may be more susceptible to POAF when nitrates are administered with antiplatelet agents. Methods Clinical records were examined from a prospectively maintained cohort of 4,124 patients undergoing primary isolated CABG surgery to identify POAF-associated factors. Results POAF risk was increased among patients receiving PINOT, and the greatest effect was observed when nitrates were administered with antiplatelet therapy. Adjustment for comorbidities did not substantively change the study results. Conclusions Administration of nitrates with certain antiplatelet agents was associated with an increased POAF risk among patients undergoing CABG surgery. Additional studies are needed to determine whether preventive strategies such as administration of antioxidants will reduce this risk.

Perioperative Inotrope Therapy and Atrial Fibrillation Following Coronary Artery Bypass Graft Surgery: Evidence of a Racial Disparity.

BACKGROUND AND OBJECTIVE: Following coronary artery bypass graft (CABG) surgery, mortality rates are significantly higher among black patients who experience postoperative atrial fibrillation (POAF). Perioperative inotropic therapy (PINOT) was associated with POAF in previous reports, but the extent to which race influences this association is unknown. In the present study, the relationship between PINOT, race, and POAF was examined in patients undergoing CABG surgery. METHODS AND SETTING: Clinical records were examined from a prospectively maintained cohort of 11,855 patients (median age 64 yrs; 70% male; 16% black) undergoing primary isolated CABG at a large cardiovascular institute in the southeastern region of the United States. Relative risk (RR) and 95% confidence intervals (CIs) were computed using log-binomial regression. MAIN RESULTS: The association between PINOT and POAF was significantly increased among black patients (adjusted RR 1.7, CI 1.4-2.0) compared with white patients (adjusted RR 1.3, CI 1.2-1.4) (pinteraction  = 0.013). CONCLUSIONS: These findings suggest that PINOT may be disproportionately associated with POAF among black patients undergoing CABG surgery. Additional studies are needed to examine further the potential underlying mechanisms of this association.

Long-Term Survival after Cardiac Surgery in Patients with Chronic Obstructive Pulmonary Disease.

BACKGROUND: Although many patients with chronic obstructive pulmonary disease (COPD) require a prolonged length of stay (PLOS) following coronary artery bypass grafting (CABG), the impact of PLOS on long-term survival has not been examined in this population. OBJECTIVES: To determine the association between PLOS and long-term survival among COPD and non-COPD patients after CABG and to examine consequent policy and practice-based implications. METHODS: A retrospective cohort study of CABG patients was conducted between 2002 and 2011. Long-term survival was compared in patients with and without COPD and stratified by PLOS. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 203 patients (4.2%) had PLOS after nonemergent CABG (N = 4801). PLOS was an important independent predictor of decreased long-term survival (no COPD, no PLOS: HR = 1.0; COPD, no PLOS: adjusted HR [95% CI], 1.8 [1.5-2.1]; no COPD, PLOS: 3.3 [2.5-4.4]; COPD, PLOS: 6.0 [4.4-8.2]; PTrend < .001). CONCLUSIONS: COPD and PLOS are 2 of many factors that affect long-term mortality in postoperative CABG patients. Aggressive treatment strategies aimed at early weaning off of mechanical ventilation and prevention of reintubation among COPD patients must be considered carefully as a means to reduce length of stay after CABG. Our results also have important implications for the long-term management of these patients and strategies for containing costs over the life course of the patient.

Comparison of Risk of Atrial Fibrillation in Black Versus White Patients After Coronary Artery Bypass Grafting.

Obesity has been identified as a risk factor for postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG). However, no studies have addressed the influence of race on this association. A total of 13,594 patients undergoing first-time, isolated CABG without preoperative AF between 1992 and 2011 were included in our study. The association between body mass index and POAF was compared by race. Relative risk and 95% CIs were computed using maximum likelihood log-binomial regression. Increasing levels of body mass index were associated with higher POAF risk after CABG in black but not white patients (pinteraction = 0.0009).

Conditional long-term survival following minimally invasive robotic mitral valve repair: a health services perspective.

BACKGROUND: Conditional survival is defined as the probability of surviving an additional number of years beyond that already survived. The aim of this study was to compute conditional survival in patients who received a robotically assisted, minimally invasive mitral valve repair procedure (RMVP). METHODS: Patients who received RMVP with annuloplasty band from May 2000 through April 2011 were included. A 5- and 10-year conditional survival model was computed using a multivariable product-limit method. RESULTS: Non-smoking men (≤65 years) who presented in sinus rhythm had a 96% probability of surviving at least 10 years if they survived their first year following surgery. In contrast, recent female smokers (>65 years) with preoperative atrial fibrillation only had an 11% probability of surviving beyond 10 years if alive after one year post-surgery. CONCLUSIONS: In the context of an increasingly managed healthcare environment, conditional survival provides useful information for patients needing to make important treatment decisions, physicians seeking to select patients most likely to benefit long-term following RMVP, and hospital administrators needing to comparatively assess the life-course economic value of high-tech surgical procedures.

Increased coronary artery disease severity in black women undergoing coronary bypass surgery.

Race and sex disparities are believed to play an important role in heart disease. The purpose of this study was to examine the association between race, sex, and number of diseased vessels at the time of coronary artery bypass grafting (CABG), and subsequent postoperative outcomes. The 13,774 patients undergoing first-time, isolated CABG between 1992 and 2011 were included. Trend in the number of diseased vessels between black and white patients, stratified by sex, were analyzed using a Cochran-Armitage trend test. Models were adjusted for age, procedural status (elective vs. nonelective), and payor type (private vs. nonprivate insurance). Black female CABG patients presented with an increasingly greater number of diseased vessels than white female CABG patients (adjusted P(trend) = 0.0021). A similar trend was not observed between black and white male CABG patients (adjusted P(trend) = 0.18). Black female CABG patients were also more likely to have longer intensive care unit and hospital lengths of stay than other race-sex groups.Our findings suggest that black female CABG patients have more advanced coronary artery disease than white female CABG patients. Further research is needed to determine the benefit of targeted preventive care and preoperative workup for this high-risk group.

Risk-adjusted survival after coronary artery bypass grafting: implications for quality improvement.

Mortality represents an important outcome measure following coronary artery bypass grafting. Shorter survival times may reflect poor surgical quality and an increased number of costly postoperative complications. Quality control efforts aimed at increasing survival times may be misleading if not properly adjusted for case-mix severity. This paper demonstrates how to construct and cross-validate efficiency-outcome plots for a specified time (e.g., 6-month and 1-year survival) after coronary artery bypass grafting, accounting for baseline cardiovascular risk factors. The application of this approach to regional centers allows for the localization of risk stratification rather than applying overly broad and non-specific models to their patient populations.

Monoamine oxidase is a major determinant of redox balance in human atrial myocardium and is associated with postoperative atrial fibrillation.

BACKGROUND: Onset of postoperative atrial fibrillation (POAF) is a common and costly complication of heart surgery despite major improvements in surgical technique and quality of patient care. The etiology of POAF, and the ability of clinicians to identify and therapeutically target high-risk patients, remains elusive. METHODS AND RESULTS: Myocardial tissue dissected from right atrial appendage (RAA) was obtained from 244 patients undergoing cardiac surgery. Reactive oxygen species (ROS) generation from multiple sources was assessed in this tissue, along with total glutathione (GSHt) and its related enzymes GSH-peroxidase (GPx) and GSH-reductase (GR). Monoamine oxidase (MAO) and NADPH oxidase were observed to generate ROS at rates 10-fold greater than intact, coupled mitochondria. POAF risk was significantly associated with MAO activity (Quartile 1 [Q1]: adjusted relative risk [ARR]=1.0; Q2: ARR=1.8, 95% confidence interval [CI]=0.84 to 4.0; Q3: ARR=2.1, 95% CI=0.99 to 4.3; Q4: ARR=3.8, 95% CI=1.9 to 7.5; adjusted Ptrend=0.009). In contrast, myocardial GSHt was inversely associated with POAF (Quartile 1 [Q1]: adjusted relative risk [ARR]=1.0; Q2: ARR=0.93, 95% confidence interval [CI]=0.60 to 1.4; Q3: ARR=0.62, 95% CI=0.36 to 1.1; Q4: ARR=0.56, 95% CI=0.34 to 0.93; adjusted Ptrend=0.014). GPx also was significantly associated with POAF; however, a linear trend for risk was not observed across increasing levels of the enzyme. GR was not associated with POAF risk. CONCLUSIONS: Our results show that MAO is an important determinant of redox balance in human atrial myocardium, and that this enzyme, in addition to GSHt and GPx, is associated with an increased risk for POAF. Further investigation is needed to validate MAO as a predictive biomarker for POAF, and to explore this enzyme's potential role in arrhythmogenesis.

The effect of race and chronic obstructive pulmonary disease on long-term survival after coronary artery bypass grafting.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a known predictor of decreased long-term survival after coronary artery bypass grafting (CABG). Differences in survival by race have not been examined. METHODS: A retrospective cohort study was conducted of CABG patients between 2002 and 2011. Long-term survival was compared in patients with and without COPD and stratified by race. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: A total of 984 (20%) patients had COPD (black n = 182; white n = 802) at the time of CABG (N = 4,801).The median follow-up for study participants was 4.4 years. COPD was observed to be a statistically significant predictor of decreased survival independent of race following CABG (no COPD: HR = 1.0; white COPD: adjusted HR = 1.9, 95% CI = 1.7-2.3; black COPD: adjusted HR = 1.6, 95% CI = 1.1-2.2). CONCLUSION: Contrary to the expected increased risk of mortality among black COPD patients in the general population, a similar survival disadvantage was not observed in our CABG population.

Preoperative atrial fibrillation and long-term survival after open heart surgery in a rural tertiary heart institute.

BACKGROUND: Preoperative atrial fibrillation (AF) is associated with increased morbidity and mortality after open heart surgery. However, the impact of preoperative AF on long-term survival after open heart surgery has not been widely examined in rural populations. Patients from rural regions are less likely to receive treatment for cardiac conditions and to have adequate medical insurance coverage. OBJECTIVE: To examine the influence of preoperative AF on long-term survival following open heart surgery in rural eastern North Carolina. METHODS: Long-term survival was compared in patients with and without preoperative AF after coronary artery bypass grafting (CABG) and CABG plus valve (CABG + V) surgery between 2002 and 2011. Hazard ratios (HR) and 95% confidence intervals (CI) were computed using a Cox regression model. RESULTS: The study population consisted of 5438 patients. A total of 263 (5%) patients had preoperative AF. Preoperative AF was an independent predictor of long-term survival (open heart surgery: adjusted HR = 1.6, 95% CI = 1.3-2.0; CABG: adjusted HR = 1.6, 95% CI = 1.3-2.1; CABG + V: adjusted HR = 1.6, 95% CI = 1.1-2.3). CONCLUSION: Preoperative AF is an important predictor of long-term survival after open heart surgery in this rural population.

Implications of Hemodialysis in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: Cardiovascular disease is the leading cause of morbidity and mortality in patients on hemodialysis. To our knowledge, no studies have examined long-term outcomes of hemodialysis patients following coronary artery bypass grafting (CABG) in a predominately rural, low-income, and racially dichotomous population. METHODS: Long-term survival of hemodialysis patients undergoing non-emergent, isolated CABG was compared with non-hemodialysis patients. Survival probabilities were computed using the Kaplan-Meier product limit method and stratified by hemodialysis. Hazard ratios (HR) and 95% confidence intervals (95%CI) were computed using a Cox regression model. RESULTS: Hemodialysis patients (n=220) had shorter long-term survival than non-hemodialysis patients (median survival=3.3 versus 14 years, p<0.0001). The survival difference remained statistically significant after adjusting for clinically relevant variables (HR=5.2, 95%CI=4.4-6.2). CONCLUSION: Hemodialysis patients had significantly shorter long-term survival compared with non-hemodialysis patients after CABG. Further research is needed to address the cost and policy implications of our findings, especially among priority populations.

Impact of timing and surgical approach on outcomes after mitral valve regurgitation operations.

BACKGROUND: This study investigated whether the timing of mitral valve (MV) repair or surgical approach affects outcomes in patients with MV regurgitation. METHODS: Between 1992 and 2009, 2,255 patients underwent MV operations, including 1,305 with isolated MV regurgitation operations (1,054 repairs, 251 replacements). Surgical approaches were sternotomy in 377, video-assisted right minithoracotomy in 481, or robot-assisted in 447. Mean follow-up was 6.4±4.5 years (maximum, 19 years). RESULTS: Sternotomy MV repairs decreased during the study while minimally invasive MV repairs increased. Robotic MV repair patients were younger, with fewer women, had better left ventricular ejection fractions, and were more likely to have myxomatous degeneration (all p<0.001). The robotic approach led to a higher MV repair rate and increased use of leaflet/chordal procedures but had longer cardiopulmonary bypass and aortic cross-clamp times (all p<0.001). The 30-day mortality for isolated MV repair was similar for all approaches (p=0.409). Fewer neurological events were observed in the videoscopic and robotic groups (p=0.013). Adjusted survival was similar for all approaches (p=0.357). Survival in patients in New York Heart Association class I to II with myxomatous degeneration or annular dilatation was similar to a matched population but was worse for patients in class III to IV or undergoing MV replacement. CONCLUSIONS: MV repair in patients with severe MV regurgitation should be performed before New York Heart Association class III to IV symptoms develop. Minimally invasive MV repair techniques render similar outcomes as the sternotomy approach.