By Jeffrey Zimmet, MD, PhD

Associate Professor of Medicine, University of California, San Francisco; Director, Cardiac Catheterization Laboratory, San Francisco VA Medical Center

SYNOPSIS: For patients hospitalized with acute heart failure, invasive coronary angiography within 14 days was associated with higher rates of coronary revascularization and lower rates of all-cause death, cardiovascular mortality, and heart failure hospitalization.

SOURCE: Kosyakovsky LB, Austin PC, Ross HJ, et al. Early invasive coronary angiography and acute ischaemic heart failure outcomes. Eur Heart J 2021;42:3756-3766.

In adult patients with congestive heart failure, the presence of coronary disease carries a worse prognosis and demands different treatments, both in terms of medical therapy and in the possibility of mechanical revascularization by bypass surgery or percutaneous interventions (PCI). However, current guidelines offer only vague direction regarding the performance and timing of coronary angiography for these patients. The relative lack of good data explains this gap.

Kosyakovsky et al sought to address this knowledge gap through an analysis of patients presenting to Canadian hospitals with heart failure and at least one feature suggesting the possible presence of underlying coronary disease: prior myocardial infarction (MI), troponin elevation, or angina. They identified patients with either early coronary angiography (defined as angiography within 14 days of presentation) or not. The primary outcome was all-cause and cardiovascular mortality. Patients were excluded if a more-detailed chart review did not indicate heart failure, or if brain natriuretic peptide (BNP) or NT-proBNP values did not support this diagnosis. Patients were similarly excluded if they showed clear contraindications to cardiac catheterization, such as severe renal failure or contrast allergy, or if they had been hospitalized recently for a pure coronary event, such as acute MI or coronary revascularization.

Ultimately, 2,994 patients were included in the study, of whom 1,567 underwent early coronary angiography and 1,427 did not. As one would expect, these groups were fundamentally different in multiple respects. Patients offered early cardiac catheterization were younger and reported higher rates of personal history of MI, angina, troponin elevation, new ST-segment changes, and reduced ejection fraction. Patients were at lower risk of early angiography if they presented with comorbidities, including dementia, COPD, higher creatinine levels, and atrial fibrillation, as well as history of coronary bypass surgery and white race. The authors used inverse probability of treatment weighting (IPTW) to adjust for baseline differences. The resulting groups recorded no significant differences in the distribution of any baseline clinical characteristics.

After weighting, both all-cause mortality (HR, 0.74; 95% CI, 0.61-0.90; P = 0.002) and cardiovascular death (HR, 0.72; 95% CI, 0.56-0.93; P = 0.012) were lower among patients who had undergone early coronary angiography, as were rates of heart failure hospitalization (adjusted HR, 0.84; 95% CI, 0.71-0.99; P = 0.042). Among patients undergoing early angiography, 58.5% were diagnosed with obstructive coronary artery disease, and just under 18% underwent revascularization within 90 days of angiography. Those undergoing early angiography recorded higher rates of coronary revascularization by PCI and bypass surgery, both at 90 days (HR, 4.69) and at two years (HR, 2.82; 95% CI, 2.06-3.86; P < 0.001).

The authors concluded early angiography in acute heart failure patients was associated with improvements in cardiovascular and all-cause mortality as well as in subsequent heart failure hospitalization. Revascularization was significantly higher among these patients. They suggested early coronary angiography should be strongly considered at the initial presentation with heart failure in the presence of features suggestive of higher ischemic risk.

COMMENTARY

This study was not a randomized trial; therefore, it is subject to unmeasured confounding despite the relatively rigorous use of IPTW analysis. Still, the robust findings here of improvements in mortality and heart failure hospitalization, correlated with more coronary revascularization out to two years, certainly provides food for thought and supports the authors’ general conclusions.

It might be best to initiate most or all components of guideline-directed medical therapy during initial hospitalization for heart failure. This could protect against subsequent outpatient providers who might be slow to add or further titrate heart failure medications downstream. The decision to offer early invasive angiography may be thought of in a similar context, where putting off this testing initially leads to inertia that is difficult to overcome later.

Obviously, each case of acute heart failure needs to be considered individually, where the risks and potential benefits of coronary angiography are weighed carefully for each patient. In situations where patients are candidates for percutaneous or surgical revascularization, or where certainty regarding the presence or absence of ischemic disease will alter medical therapy, timely cardiac catheterization is worth thorough consideration at the time of acute heart failure presentation.