Coronary Bypass Surgery for Patients with Chronic Poor Preoperative Left Ventricular Function (EF<30%): 5-year Follow-up

Single versus bilateral internal thoracic artery grafting in patients with low ejection fraction

Coronary artery bypass grafting (CABG) is the standard of care for the treatment of complex coronary artery disease. However, the optimal surgical treatment for patients with reduced left ventricular function with low ejection fraction (EF) is inconclusive. In our center, left-sided coronary grafting with bilateral internal thoracic artery (BITA) is generally the preferred method for surgical revascularization, also for patients with low EF. We compared early and long-term outcomes between BITA grafting and single internal thoracic artery (SITA) grafting in patients with low EF.We evaluated short- and long-term outcomes of all patients who underwent surgical revascularization in our center during 1996 to 2011, according to EF ≥30% and <30%. Univariate and multivariate analyses were performed. In addition, patients who underwent BITA and SITA grafting were matched using propensity score matching.In total, 5337 patients with multivessel disease underwent surgical revascularization during the study period. Of them, 394 had low EF. Among these, 188 underwent SITA revascularization and 206 BITA grafting. Those who underwent SITA were more likely to have comorbidities such as chronic obstructive pulmonary disease, diabetes, congestive heart failure, chronic renal failure, and a critical preoperative condition including preoperative intra-aortic balloon pump insertion.Statistically significant differences were not observed between the SITA and BITA groups in 30-day mortality (8.5% vs 6.8%, P = .55), sternal wound infection (2.7% vs 1.0%, P = .27), stroke (3.7% vs 6.3%, P = .24), and perioperative myocardial infarction (5.9% vs 2.9%, P = .15). Long-term survival (median follow up of 14 years, interquartile range, 11.2-18.9) was also similar between the groups. Propensity score matching (129 matched pairs) yielded similar early and long-term outcomes for the groups.This study did not demonstrate any clinical benefit for BITA compared with SITA revascularization in individuals with low EF.

Bilateral internal thoracic artery grafting improves long-term survival in patients with reduced ejection fraction: a propensity-matched study with 30-year follow-up

OBJECTIVE

Bilateral internal thoracic artery (BITA) grafting has been shown to improve long-term survival after coronary artery bypass grafting. However, there has been reluctance to use this technique in higher-risk patients. Patients with reduced ejection fraction (EF) have been shown to present a higher operative risk and reduced long-term survival. We studied the perioperative and long-term results of BITA versus single internal thoracic artery grafting (SITA) in a large population of patients with reduced EF in whom BITA grafting was broadly applied.

METHODS

Between February 1972 and May 1994, 4537 consecutive patients in whom EF was recorded underwent SITA (2340) or BITA (2197) grafting. Prospectively collected clinical data recorded EF categorically as less than 0.30 (group I; n = 233), 0.30 to 0.50 (group II; n = 1256), or greater than 0.50 (group III; n = 3048). Multivariable analyses were performed to determine correlates of operative and late mortality. Optimal matching using propensity scoring was used to create matched SITA and BITA cohorts: group I, SITA and BITA, n = 87 each; group II, SITA and BITA, n = 448 each; group III, SITA and BITA, n = 1137 each. Equality of survival distribution was tested by the log-rank algorithm.

RESULTS

There was no difference in operative mortality between matched SITA and BITA groups (group I: SITA vs BITA, 10.3% vs 6.9%, P = .418; group II: 4.7% vs 4.5%, P = .873; group III: 3.2% vs 2.0%, P = .086). SITA versus BITA was not a predictor of operative mortality on logistic regression analysis. There was no difference in freedom from any postoperative complication, including sternal wound infection, between matched SITA and BITA groups. Late survival was significantly enhanced with the use of BITA grafting in groups II and III (10- and 20-year survival, SITA vs BITA, in group II: 57.7% ± 0.3% and 19% ± 2.5% vs 62.0% ± 2.3% and 33.1% ± 3.4%, respectively, P = .016; and in group III: 67.1% ± 1.4% and 35.8% ± 1.7% vs 74.6% ± 1.3% and 38.1% ± 2.1%, respectively, P = .012). Likewise, choice of SITA versus BITA was a significant predictor of late mortality on Cox regression in both groups II (P < .007) and III (P < .001).

CONCLUSIONS

Broadly applied BITA compared with SITA grafting in propensity-matched patients provides enhanced long-term survival with no increase in operative mortality or morbidity for patients with normal and reduced EF. The expanded use of BITA grafting should be seriously considered.

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.

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

BACKGROUND

In this prospective study, we investigated the determinants of long-term outcome, symptoms, and left ventricular function after coronary artery bypass grafting in patients with a moderate to severely decreased left ventricular ejection fraction.

METHODS

Between 1997 and 1998, 75 consecutive patients with moderate to severe left ventricular dysfunction underwent coronary artery bypass grafting procedures. The operative mortality rate was 4.0%, and the 72 survivors were monitored for 8 years. The end points were mortality, symptomatic status (New York Heart Association [NYHA] functional class), and left ventricular function.

RESULTS

The total survival rate after 8 years was 89.3%. During follow-up, 8 patients died. Death was attributed to a cardiac cause in 5 patients and to a noncardiac cause in 3. There was no statistically significant difference between preoperative and late postoperative NYHA functional class, despite a statistically significant improvement that persisted for up to 4 years after CABG. The results of echocardiography showed a statistically significant improvement in the left ventricular ejection fraction (from 0.322 +/- 0.06 preoperatively to 0.463 +/- 0.02 at follow-up, p < 0.001). Multivariate analysis revealed that the left ventricular end-systolic volume index, the presence of angina pectoris, and absence of symptoms of congestive heart failure were preoperative indicators of freedom from heart failure after coronary operations (p < 0.05).

CONCLUSIONS

Coronary artery bypass grafting for patients with moderate-to-severe left ventricular dysfunction is associated with acceptable long-term results. The left ventricular end-systolic volume index is a simple noninvasive method to aid in the preoperative decision making in such patients.