Journal Articles

Publication Date

1-1-2023

Journal

JACC: Cardiovascular Imaging

Abstract

BACKGROUND: Subendocardial ischemia is commonly diagnosed but not quantified by imaging.

OBJECTIVES: This study sought to define size and severity of subendocardial and transmural stress perfusion deficits, clinical associations, and outcomes.

METHODS: Regional rest-stress perfusion in mL/min/g, coronary flow reserve, coronary flow capacity (CFC), relative stress flow, subendocardial stress-to-rest ratio and stress subendocardial-to-subepicardial ratio as percentage of left ventricle were measured by positron emission tomography (PET) with rubidium Rb 82 and dipyridamole stress in serial 6,331 diagnostic PETs with prospective 10-year follow-up for major adverse cardiac events with and without revascularization.

RESULTS: Of 6,331 diagnostic PETs, 1,316 (20.7%) had severely reduced CFC with 41.4% having angina or ST-segment depression (STΔ) >1 mm during hyperemic stress, increasing with size. For 5,015 PETs with no severe CFC abnormality, 402 (8%) had angina or STΔ during stress, and 82% had abnormal subendocardial perfusion with 8.7% having angina or STΔ >1 mm during dipyridamole stress. Of 947 cases with stress-induced angina or STΔ >1 mm, 945 (99.8%) had reduced transmural or subendocardial perfusion reflecting sufficient microvascular function to increase coronary blood flow and reduce intracoronary pressure, causing reduced subendocardial perfusion; only 2 (0.2%) had normal subendocardial perfusion, suggesting microvascular disease as the cause of the angina. Over 10-year follow-up (mean 5 years), severely reduced CFC associated with major adverse cardiac events of 44.4% compared to 8.8% for no severe CFC (unadjusted P < 0.00001) and mortality of 15.2% without and 6.9% with revascularization (P < 0.00002) confirmed by multivariable Cox regression modeling. For no severe CFC, mortality was 3% with and without revascularization (P = 0.90).

CONCLUSIONS: Reduced subendocardial perfusion on dipyridamole PET without regional stress perfusion defects is common without angina, has low risk of major adverse cardiac events, reflecting asymptomatic nonobstructive diffuse coronary artery disease, or angina without stenosis. Severely reduced CFC causes angina in fewer than one-half of cases but incurs high mortality risk that is significantly reduced after revascularization.

Keywords

Humans, Coronary Artery Disease, Prevalence, Prospective Studies, Coronary Circulation, tomography, X-Ray Computed, Predictive Value of Tests, Myocardial Ischemia, Angina Pectoris, Dipyridamole, Myocardial Perfusion Imaging

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.