Results and predictors of early and late outcome of coronary artery bypass grafting in patients with severely depressed left ventricular function

Survival, clinical status and quality of life five years after coronary surgery. The ARCA study

INTRODUCTION AND OBJECTIVES

Little is known about the long-term outcomes of coronary surgery and their determinants in Spain. The objectives of this study were to evaluate clinical outcomes, quality of life and survival in a cohort of patients 5 years after undergoing a first aortocoronary bypass operation without any other associated procedure.

METHODS

Patients who survived the operation and whose pre- and postoperative data had been collected prospectively were followed up by telephone interview after 5 years.

RESULTS

Information was available after 5 years on 1,300 (85.2%) of the 1,525 patients who survived until hospital discharge. Of these, 13.6% had died, while 24% had either died, undergone revascularization or were readmitted because of a cardiac complaint. The cumulative survival rate (excluding the period of hospitalization) was 0.87 (95% confidence interval, 0.85-0.89). Mortality varied significantly with the level of preoperative risk (i.e. the EuroSCORE), to the extent that mortality in the low-risk group was equivalent to that in the general reference population.

CONCLUSIONS

Three-quarters of patients who survived until hospital discharge after coronary surgery did not experience a major cardiac event within 5 years and their level of functioning and quality of life were good. The survival rate after the immediate postoperative period varied according to the patient's preoperative risk profile and, in low-risk patients, was equivalent to that in the general reference population.

Long-term outcome of coronary artery bypass grafting in patients with left ventricular dysfunction

BACKGROUND

Coronary artery bypass grafting (CABG) is a well-accepted therapeutic strategy for patients with multivessel coronary artery disease and left ventricular dysfunction. The aim of the study was to evaluate long-term results after CABG in patients with preoperative left ventricular ejection fraction (LVEF) of 0.35 or less.

METHODS

Data from 302 consecutive patients (mean age, 62 +/- 8.7 years) with LVEF of 0.35 or less who had undergone CABG were analyzed. Epinephrine and enoximone with or without norepinephrine were used to increase cardiac index. Intra-aortic balloon pump or left ventricular assist devices, or both, were used in case of postoperative low output syndrome.

RESULTS

Complete revascularization was achieved in 298 of 302 patients (98.7%); internal thoracic artery was used in 294 (97.4%). Operative mortality was 5.3%; independent predictors of operative mortality were emergency CABG (p = 0.005), history of ventricular arrhythmias (p = 0.007), and previous anterior myocardial infarction (p = 0.05). At follow-up, all-cause mortality was 30.8%, and 10-year survival was 63% +/- 4%; independent predictors of late all-cause mortality were history of ventricular arrhythmias (p < 0.0001), chronic renal dysfunction (p = 0.0004), and diabetes mellitus (p = 0.04). Cardiac death was 20.4%, and 10-year freedom from cardiac death was 73% +/- 3.3%; independent predictors of cardiac death were history of ventricular arrhythmias (p = 0.004), chronic renal dysfunction (p = 0.03), and more than one previous anterior myocardial infarction (p = 0.004). At 80 +/- 44 months of follow-up, echocardiography showed significant LVEF improvement (0.43 +/- 0.09 versus 0.28 +/- 0.06, p < 0.0001). Ten-year freedom from myocardial infarction was 87% +/- 3%.

CONCLUSIONS

Excellent long-term results after CABG can be expected for patients with LVEF of 0.35 or less. Complete revascularization and internal thoracic artery grafting are associated with high freedom from myocardial infarction. Careful treatment of arrhythmias, diabetes, and renal dysfunction is necessary to improve long-term survival.

Survival after isolated coronary artery bypass grafting in patients with severe left ventricular dysfunction

BACKGROUND

The number of patients with severe left ventricular dysfunction referred for coronary artery bypass graft surgery (CABG) continues to increase. The aim of this study was to document the long-term survival in this group.

METHODS

The 30-day mortality and long-term survival outcome of 162 patients with severely depressed left ventricular ejection fraction (LVEF [< or = 30%]) who had consecutive isolated CABG between 1996 and 2005 were compared with 661 patients who had impaired LVEF (31% to 59%) and 1,231 patients with normal LVEF (> or = 60%).

RESULTS

The 30-day mortality for patients with severely depressed LVEF was 5.6%. The median survival for deceased patients was 3.4 years (interquartile range, 1.3 to 5.9). The risk of all-cause mortality attributable to severe left ventricular dysfunction was increased twofold compared with having normal LVEF (hazard ratio = 2.28; 95% confidence interval: 1.64 to 3.18; p < 0.001). Among the covariates, older age, emergency surgery, mitral incompetence, smoking history, respiratory disease, diabetes mellitus, cerebrovascular disease, intensive care unit intubation for 24 hours or more, postoperative renal failure, postoperative pleural effusion, and nonuse of left internal mammary artery were detected as significant predictors of increased mortality risk.

CONCLUSIONS

The mortality rate among CABG patients with severely depressed LVEF was comparable to that reported in other series. Severe left ventricular dysfunction carried more than a twofold increased mortality risk compared with patients who had an impaired LVEF, adjusted for traditional risk factors. These data suggest that LVEF has an impact on long-term patient survival even after preoperative covariates and postoperative morbidity outcomes are considered.

Comorbidity in patients undergoing coronary artery bypass graft surgery: impact on outcome and implications for cardiac rehabilitation

The increasing comorbid disease burden among patients undergoing coronary artery bypass graft surgery (CABG) and the improved operative survival are expanding the number of post-CABG patients living with prognostically significant comorbidities. In a large contemporary database, 29.9% of the patients receiving isolated CABG had diabetes mellitus, 16% peripheral vascular disease, 18.6% chronic obstructive pulmonary disease, and 27.5% renal dysfunction. Patients with comorbidity are more likely to be old and often female, may have special care-requirements early after discharge, and are at increased risk for adverse outcomes. Contemporary available evidence indicates that older individuals, women, and patients with comorbidities are significantly less likely to receive cardiac rehabilitation. In addition, compliance with proven atherosclerosis risk reduction strategies for CABG patients is suboptimal. In this article we will review the impact of comorbidity on short-term and long-term outcome after CABG and their implications for cardiac rehabilitation.