Baseline Predictors of Low-Density Lipoprotein Cholesterol and Systolic Blood Pressure Goal Attainment After 1 Year in the ISCHEMIA Trial

Abstract

Background: Risk factor control is the cornerstone of managing stable ischemic heart disease but is often not achieved. Predictors of risk factor control in a randomized clinical trial have not been described. Methods and Results: The ISCHEMIA trial (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) randomized individuals with at least moderate inducible ischemia and obstructive coronary artery disease to an initial invasive or conservative strategy in addition to optimal medical therapy. The primary aim of this analysis was to determine predictors of meeting trial goals for LDL-C (low-density lipoprotein cholesterol, goal <70 mg/dL) or systolic blood pressure (SBP, goal <140 mm Hg) at 1 year post-randomization. We included all randomized participants in the ISCHEMIA trial with baseline and 1-year LDL-C and SBP values by January 28, 2019. Among the 3984 ISCHEMIA participants (78% of 5179 randomized) with available data, 35% were at goal for LDL-C, and 65% were at goal for SBP at baseline. At 1 year, the percent at goal increased to 52% for LDL-C and 75% for SBP. Adjusted odds of 1-year LDL-C goal attainment were greater with older age (odds ratio [OR], 1.11 [95% CI, 1.03–1.20] per 10 years), lower baseline LDL-C (OR, 1.19 [95% CI, 1.17–1.22] per 10 mg/dL), high-intensity statin use (OR, 1.30 [95% CI, 1.12–1.51]), nonwhite race (OR, 1.32 [95% CI, 1.07–1.63]), and North American enrollment compared with other regions (OR, 1.32 [95% CI, 1.06–1.66]). Women were less likely than men to achieve 1-year LDL-C goal (OR, 0.68 [95% CI, 0.58–0.80]). Adjusted odds of 1-year SBP goal attainment were greater with lower baseline SBP (OR, 1.27 [95% CI, 1.22–1.33] per 10 mm Hg) and with North American enrollment (OR, 1.35 [95% CI, 1.04–1.76]). Conclusions: In ISCHEMIA, older age, male sex, high-intensity statin use, lower baseline LDL-C, and North American location predicted 1-year LDL-C goal attainment, whereas lower baseline SBP and North American location predicted 1-year SBP goal attainment. Future studies should examine the effects of sex disparities, international practice patterns, and provider behavior on risk factor control.