Guideline-Directed Medical Therapy and Outcomes in the ISCHEMIA Trial

Abstract

Background

Guideline-directed medical therapy (GDMT) with multiple risk factor goals is recommended for patients with chronic coronary disease (CCD), yet achieving all GDMT goals is uncommon. The relative importance of these goals and timing of their attainment on cardiovascular events is uncertain.

Objectives

This study aims to describe the relationship between achieving specific GDMT goals, when they are achieved, and clinical outcomes.

Methods

This was an observational study of participants with CCD in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial. The primary outcome was cardiovascular (CV) death or myocardial infarction (MI). GDMT goals were systolic blood pressure (SBP) <130 mm Hg, low-density lipoprotein cholesterol <70 mg/dL, not smoking, and antiplatelet therapy. Frequency of GDMT goals met at baseline and during follow-up is described. Bayesian joint modeling for longitudinal goal status and time-to-event analyses characterized the relative importance of specific GDMT goal attainment and timing with CV death/MI.

Results

All 5,179 ISCHEMIA participants were included. Among 4,914 participants with complete data on all 4 GDMT goals at baseline, 386 (9%), 2,073 (42%), 1,843 (38%), and 612 (12%) met 0-1, 2, 3, and 4 GDMT goals, respectively. The 4-year cumulative event rate for CV death/MI was highest for participants who attained no GDMT goals (24.5%; 95% credible interval [CrI]: 13.5%-42.2%) and lowest for those who attained all goals at baseline and remained at goal during follow-up (8.7%; 95% CrI: 6.7%-10.9%). SBP goal attainment was associated with a significant absolute event reduction in CV death/MI (–5.1%; 95% CrI: –11.3% to –1.0%), followed by antiplatelet therapy (–11.2%; 95% CrI: –29.1% to 0.8%), achieving low-density lipoprotein cholesterol <70 mg/dL (–2.0%; 95% CrI: –6.0% to 2.4%), and not smoking (–1.7%; 95% CrI: –9.3% to 4.2%). Ten millimeters of mercury lower SBP during follow-up was associated with 10% relative risk reduction of CV death/MI (RR [relative risk] = 0.90; 95% CrI: 0.82-0.98), after adjusting for other GDMT goals and baseline characteristics.

Conclusions

Among participants with CCD, early attainment and maintenance of GDMT goals, especially SBP, were associated with fewer cardiovascular events. Compared with no GDMT goals at target, having all 4 GDMT goals at target at baseline was associated with an absolute 16% fewer CV deaths and MIs. (ISCHEMIA [International Study of Comparative Health Effectiveness With Medical and Invasive Approaches]; NCT01471522)