Stable ischemic heart disease in the older adults.

Abstract

Ischemic heart disease is caused by atherosclerotic and/or thrombotic obstruction of coronary arteries. Clinical spectrum of ischemic heart disease expands from asymptomatic atherosclerosis of coronary arteries to acute coronary syndromes (ACS) including unstable angina, acute myocardial infarction (non-ST elevation myocardial infarction and ST elevation myocardial infarction). Stable ischemic heart disease (SIHD) refers to patients with known or suspected SIHD who have no recent or acute changes in their symptomatic status, suggesting no active thrombotic process is underway. These patients include those with (1) recent-onset or stable angina or ischemic equivalent symptoms, such as dyspnea or arm pain with exertion; (2) post-ACS stabilized after revascularization or medical therapy; and (3) asymptomatic SIHD diagnosed by abnormal stress tests or imaging studies. This review summarizes clinical features and management of SIHD in the older adult. ACS in older adults is not considered in this review. Age is a strong independent risk factor for the development of atherosclerotic arterial disease. In the coming decades, tremendous increase of the prevalence of SIHD in the older adults is projected for the following reasons: (1) The world's population is aging, with those aged 80 and older expanding most rapidly. (2) The elderly population makes up the majority of new angina pectoris patients. In the USA, the annual rates per 1000 population of new episodes of angina pectoris of nonblack men were reported to be 28.3 for those 65 to 74 years of age, 36.3 for 75 to 84 years of age and 33.0 for ≥ 85 years of age; and 14.1, 20.0 and 22.0 for nonblack women in the same age groups; 22.4, 33.8 and 39.5 for black women; 15.3, 23.6 and 35.9 for black women, respectively.[1] (3) The acute myocardial infarction (AMI) survival rate has improved dramatically under current ACS care, so large numbers of AMI patients become SIHD patients. (4) The increased use of non-invasive (coronary artery calcium score, coronary CT angiography, etc) and invasive diagnostic modalities adds significantly to the number diagnosed with SIHD. SIHD in the older adult presents unique challenges to the healthcare community with predictable increasing burden but less clinical evidence to guide practice. In the older adults, SIHD has equal prevalence in men and women. Obstructive coronary artery disease (CAD) is often more diffuse and severe anatomically. These patients have higher prevalence of left main stenosis, multi-vessel disease and impaired left ventricular function than in younger patients. In this population, other pathophysiological mechanisms may also cause myocardial ischemia and contribute to SIHD clinical presentation. These include microvascular dysfunction, endothelial dysfunction, vascular spasm or micro-embolism, left ventricular hypertrophy associated microvascular insufficiency or other factors contributing to supply-demand imbalance.[2] Microvascular and endothelial dysfunction are common in the older adult population. Therefore, SIHD in the older adult requires a comprehensive approach, not only diagnosing and treating obstructive CAD, but also managing other potential etiologies.