Stress myocardial perfusion imaging by CMR provides strong prognostic value to cardiac events regardless of patient's sex

Abstract

Objectives: The major aim of this study is to test the hypothesis that stress cardiac magnetic resonance (CMR) imaging can provide robust prognostic value in women presenting with suspected ischemia, to the same extent as in men.

Background: Compelling evidence indicates that women with coronary artery disease (CAD) experience worse outcomes than men owing to a lack of early diagnosis and management. Numerous clinical studies have shown that stress CMR detects evidence of myocardial ischemia and infarction at high accuracy. Compared to nuclear scintigraphy, CMR is free of ionizing radiation, has high spatial resolution for imaging small hearts, and overcomes breast attenuation artifacts, which are substantial advantages when imaging women for CAD.

Methods: We performed stress CMR in 405 patients (168 women, mean age 58 ± 14 years) referred for ischemia assessment. CMR techniques included cine cardiac function, perfusion imaging during vasodilating stress, and late gadolinium enhancement imaging. All patients were followed for major adverse cardiac events (MACE).

Results: At a median follow-up of 30 months, MACE occurred in 36 patients (9%) including 21 cardiac deaths and 15 acute myocardial infarctions. In women, CMR evidence of ischemia (ISCHEMIA) demonstrated strong association with MACE (unadjusted hazard ratio: 49.9, p < 0.0001). While women with ISCHEMIA(+) had an annual MACE rate of 15%, women with ISCHEMIA(-) had very low annual MACE rate (0.3%), which was not statistically different from the low annual MACE rate in men with ISCHEMIA(-) (1.1%). CMR myocardial ischemia score was the strongest multivariable predictor of MACE in this cohort, for both women and men, indicating robust cardiac prognostication regardless of sex.

Conclusions: In addition to avoiding exposure to ionizing radiation, stress CMR myocardial perfusion imaging is an effective and robust risk-stratifying tool for patients of either sex presenting with possible ischemia.

Figure 1. Kaplan-Meier Curves for MACE and Cardiac Death

Kaplan-Meier curves for major adverse cardiac events (MACE) (A) and cardiac death (B) stratified by evidence of ischemia in each sex.

Figure 2. Patient Annual Event Rates of MACE and of Cardiac Death

Patient annual event rates of major adverse cardiac events (MACE) and cardiac death, stratified by sex and evidence of ischemia. Ischemia − = evidence of ischemia absent; ischemia + = evidence of ischemia present.

Figure 3. Stress CMR Study From a 47-Year-Old Woman With a Previous MI Referred for Assessment of Myocardial Ischemia

Mid and apical short-axis views of the stress perfusion images show an extensive perfusion defect within the mid and apical inferior, inferoseptal, and inferolateral walls (red arrows) (A,C). Matching late gadolinium enhancement (B,D) demonstrates a small subendocardial myocardial infarction (MI) within the mid-inferior wall. CMR = cardiac magnetic resonance; LV = left ventricle; RV = right ventricle.