Diabetes Associated With Greater Ejection Fraction Improvement After Revascularization in Patients With Reduced Ejection Fraction

Extreme Risk of Sudden Cardiac Death within Three Months after Revascularization in Patients with Ischemic Left Ventricular Systolic Dysfunction

Background

The risk of sudden cardiac death (SCD) after coronary revascularization in patients with left ventricular (LV) systolic dysfunction has not been characterized completely. This study aims to evaluate the incidence and time course of SCD after revascularization in such patients. The determinants of SCD within 3 months after revascularization were also assessed.

Methods

A cohort study of patients with reduced ejection fraction (EF ≤ 40%), who underwent revascularization was performed. The incidence of SCD was estimated to account for the competing risk of deaths due to other causes.

Results

2317 patients were enrolled. With a median follow-up of 3.5 years, 162 (32.1%) of the 504 deaths were due to SCD. The risk of SCD was highest in the first 3 months after revascularization, with an incidence rate of 0.37%/month. The event rate decreased to 0.12%/month, 0.08%/month, 0.09%/month, 0.14%/month, and 0.19%/month at 3-6 months, 6-12 months, 1-3 years, 3-5 years, and 5-10 years, respectively. A history of ventricular tachycardia/ventricular fibrillation (hazard ratio [HR], 5.55; 95% confidence interval [CI], 1.33-23.19; p = 0.019) and triple vessel disease (HR, 3.90; 95% CI, 1.38-11.05; p = 0.010) were associated with the risk of SCD within 3 months. However, preoperative EF (in 5% increments) was not predictive (HR per 5% increase, 0.98; 95% CI, 0.62-1.55; p = 0.935).

Conclusions

For patients with LV dysfunction, the risk of SCD was the highest during the first 3 months after revascularization. Further risk classification and treatment strategy are warranted.

Clinical Trial Registration

The name of the registry: Coronary Revascularization in Patients with Ischemic Heart Failure and Prevention of Sudden Cardiac Death. Registration number: ChiCTR2100044378.

Smaller left ventricular end-systolic diameter and lower ejection fraction at baseline associated with greater ejection fraction improvement after revascularization among patients with left ventricular dysfunction

Objectives

To investigate the predictive roles of pre-operative left ventricular (LV) size and ejection fraction (EF) in EF improvement and outcome following revascularization in patients with coronary artery disease (CAD) and LV dysfunction.

Background

Revascularization may improve EF and long-term outcomes of patients with LV dysfunction. However, the determinants of EF improvement have not yet been investigated comprehensively.

Materials and methods

Patients with EF measurements before and 3 months after revascularization were enrolled in a cohort study (No. ChiCTR2100044378). All patients had baseline EF ≤ 40%. EF improvement was defined as absolute increase in EF > 5%. According to LV end-systolic diameter (LVESD) (severely enlarged or not) and EF (≤35% or of 36–40%) at baseline, patients were categorized into four groups.

Results

A total of 939 patients were identified. A total of 549 (58.5%) had EF improved. Both LVESD [odds ratio (OR) per 1 mm decrease, 1.05; 95% CI, 1.04–1.07; P < 0.001] and EF (OR per 1% decrease, 1.06; 95% CI, 1.03–1.10; P < 0.001) at baseline were predictive of EF improvement after revascularization. Patients with LVESD not severely enlarged and EF ≤ 35% had higher odds of being in the EF improved group in comparison with other three groups both in unadjusted and adjusted analysis (all P < 0.001). The median follow-up time was 3.5 years. Patients with LVESD not severely enlarged and EF ≤ 35% had significantly lower risk of all-cause death in comparison with patients with LVESD severely enlarged and EF ≤ 35% [hazard ratio (HR), 2.73; 95% CI, 1.28–5.82; P = 0.009], and tended to have lower risk in comparison with patients with LVESD severely enlarged and EF of 36–40% (HR, 2.00; 95% CI, 0.93–4.27; P = 0.074).

Conclusion

Among CAD patients with reduced EF (≤ 40%) who underwent revascularization, smaller pre-operative LVESD and lower EF had greatest potential to have EF improvement and better outcome. Our findings imply the indication for revascularization in patients with LV dysfunction who presented with lower EF but smaller LV size.

Extent of Ejection Fraction Improvement After Revascularization Associated with Outcomes Among Patients with Ischemic Left Ventricular Dysfunction

Purpose

Ejection fraction (EF) has been reported to be a major predictor of improved survival in patients with heart failure. However, it is largely unknown whether the extent of improvement in EF affects the subsequent risk of mortality. This study sought to investigate change in EF after revascularization and the implication of these changes on clinical outcomes among patients with ischemic left ventricular dysfunction.

Patients and Methods

We conducted a cohort study (No. ChiCTR2100044378) of patients with reduced EF (≤40%) who received revascularization and had EF reassessment by echocardiography 3 months after revascularization. Patients were categorized according to the absolute change in EF: 1) EF worsened group (absolute decrease in EF >5%); 2) EF unchanged group (absolute change in EF −5% to 5%); 3) EF improved group (absolute increase in EF >5%).

Results

Of 974 patients, 84 (8.6%) had EF worsened, 317 (32.5%) had EF unchanged and 573 (58.8%) had EF improved. The median follow-up time was 3.5 years, during which 143 patients died. For each 5-unit increments in EF, the risk of death decreased by 20% (hazard ratio, HR, per 5% increases, 0.80; 95% CI, 0.73–0.86; P<0.001). Compared with EF improvement group, patients with EF worsened (HR, 3.35; 95% CI, 2.07–5.42; P<0.001) and patients with EF unchanged (HR, 2.05; 95% CI, 1.40–3.01; P<0.001) had significantly higher risk of all-cause death.

Conclusion

Changes in EF were inversely associated with the risk of mortality. The extent of EF improvement after revascularization might be a potential factor which defines clinical outcomes.