Comparison of mid-term mortality after surgical, supported or unsupported percutaneous revascularization in patients with severely reduced ejection fraction: A direct and network meta-analysis of adjusted observational studies and randomized-controlled

Utility of coronary revascularization in patients with ischemic left ventricular dysfunction

BACKGROUND

Revascularization in patients with left ventricular (LV) dysfunction has been a subject of ongoing uncertainty and conflicting results. This is further complicated by factors including viability, severity of LV dysfunction, and method of revascularization using percutaneous coronary intervention (PCI) versus coronary-artery bypass grafting (CABG).

OBJECTIVES

The purpose of this meta-analysis is to evaluate the association of coronary revascularization with outcomes in patients with ischemic LV dysfunction.

METHODS

A literature search was conducted for studies reporting on cardiovascular outcomes after revascularization compared to optimal medical therapy (OMT) in patients with ischemic LV dysfunction.

RESULTS

A total of 23 studies with 10,110 participants met inclusion criteria. Revascularization was significantly associated with lower all-cause mortality and CV mortality compared to OMT. The association was statistically significant regardless of severity of LV dysfunction or method of revascularization. Subgroup analysis demonstrated that revascularization was significantly associated with lower all-cause and CV mortality compared to OMT for patients with viable myocardium and mixed cohorts with variable viability, but not patients without viable myocardium. Revascularization was not associated with a significant difference in risk of heart failure (HF) hospitalization or acute myocardial infarction (AMI) compared to OMT.

CONCLUSIONS

Revascularization in patients with ischemic LV dysfunction is associated with lower risk of all-cause and CV mortality independent of severity of LV dysfunction or method of revascularization. Revascularization is not associated with lower risk of mortality in patients without evidence of viable myocardium and is not associated with lower risk of AMI or HF hospitalization.

Predictors of left ventricular ejection fraction in high-risk percutaneous coronary interventions

Revascularization completeness after percutaneous coronary intervention (PCI) is associated with improved long-term outcomes. Mechanical circulatory support [intra-aortic balloon pump (IABP) or Impella] is used during high-risk PCI (HR-PCI) to enhance peri-procedural safety and achieve more complete revascularization. The relationship between revascularization completeness [post-PCI residual SYNTAX Score (rSS)] and left ventricular ejection fraction (LVEF) in HR-PCI has not been established. We investigated LVEF predictors at 90 days post-PCI with Impella or IABP support. Individual patient data (IPD) were analyzed from PROTECT II (NCT00562016) in the base case. IPD from PROTECT II and RESTORE-EF (NCT04648306) were naïvely pooled in the sensitivity analysis. Using complete cases only, linear regression was used to explore the predictors of LVEF at 90 days post-PCI. Models were refined using stepwise selection based on Akaike Information Criterion and included: treatment group (Impella, IABP), baseline characteristics [age, gender, race, New York Heart Association Functional Classification, LVEF, SYNTAX Score (SS)], and rSS. Impella treatment and higher baseline LVEF were significant predictors of LVEF improvement at 90 days post-PCI (p ≤ 0.05), and a lower rSS contributed to the model (p = 0.082). In the sensitivity analysis, Impella treatment, higher baseline LVEF, and lower rSS were significant predictors of LVEF improvement at 90 days (p ≤ 0.05), and SS pre-PCI contributed to the model (p = 0.070). Higher baseline LVEF, higher SS pre-PCI, lower rSS (i.e. completeness of revascularization), and Impella treatment were predictors of post-PCI LVEF improvement. The findings suggest potential mechanisms of Impella include improving the extent and quality of revascularization, and intraprocedural ventricular unloading.