Abstract
Background: The ISCHEMIA trial demonstrated no overall prognostic benefit of an initial invasive strategy over optimal medical therapy (OMT) in patients with chronic coronary syndrome (CCS) and moderate-to-severe ischemia. However, managing patients with stable angina and low systolic blood pressure (SBP) remains challenging due to limited tolerance to vasodilatory anti-anginal drugs and the uncertain role of revascularization in improving long-term outcomes for this subgroup. Objectives: This study aimed to estimate the treatment effect of an initial invasive strategy (INV) compared with conservative medical therapy (CON) on long-term clinical outcomes and quality of life in patients with stable angina, particularly those with low baseline systolic blood pressure (≤120 mmHg). Methods: We conducted a post hoc analysis of 3544 patients with stable angina from the ISCHEMIA trial, divided into an initial invasive strategy or a conservative approach. The primary endpoint was a 3-year composite of cardiovascular death, myocardial infarction, hospitalization for unstable angina or heart failure, or resuscitated cardiac arrest. Health-related quality of life was assessed using the Seattle Angina Questionnaire (SAQ). In the subgroup, patients were stratified by baseline SBP, diastolic blood pressure (DBP) and heart rate; the Cox model was adjusted for the covariates. Results: Baseline characteristics were generally comparable between the two groups. Over 3 years of follow-up, no significant difference in primary endpoint events was observed between the INV and CON group in the overall cohort (HR = 0.94, 95%CI 0.77-1.14, p = 0.53), and the INV group had the higher SAQ score. Among patients with low baseline SBP (≤120 mmHg), after adjusting for clinical factors using Cox regression, randomized treatment assignment to the INV approach significantly reduced adverse cardiovascular events compared with conservative therapy (HR = 0.58, 95%CI 0.38 to 0.89). Conclusions: In patients with stable angina, an invasive strategy improved long-term quality of life. Among those with low baseline SBP (≤120 mmHg) and limited tolerance to vasodilatory anti-anginal drugs, invasive management reduced 3-year adverse events, supporting tailored revascularization strategies for these patients; a larger cohort is needed for validation. However, this subgroup-specific causal contrast derives from a post hoc exploratory analysis and should be interpreted cautiously; prospective randomized studies are needed to further validate these findings.