Does revascularization improve quality of life in elderly diabetic patients with angina pectoris?

It is difficult to make generalizations about treatment of elderly diabetic patients with coronary artery disease (CAD). This is a heterogeneous population with marked individual variation in risk and prognosis. In the United States, a man reaching the age of 80 can expect to live, on average, an additional 6.76 years, whereas a woman may live 9.14 years. Healthy life expectancy, however, is not rising as fast as total life expectancy; there is currently about a 10-year difference between these values. This is particularly true of pa­tients with diabetes. Diabetes mellitus not only shortens longevity, it also

dramatically

decreases healthy life expectancy.

Both diabetes mellitus and advanced age increase the risks of revascularization.^1-3 Both are associated with comorbidities of renal insufficiency and noncardiac atherosclerotic vascular disease. Increasing age is an independent predictor of mortality from coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI). Pa­tients with diabetes, as compared with those without diabetes, also typically demonstrate earlier, more extensive and diffuse coronary disease, and greater depression of systolic function with an increased prevalence of clinical heart failure. Noncardiovascular issues also become important in treating elderly diabetic patients: activity is limited, dementia is prevalent, and concurrent illnesses are frequent. In diabetic patients facing surgical revascularization there are increased concerns regarding deep wound infections and wound healing and the effect of a prolonged convalescent course on quality of life. Redoing a cardiothoracic procedure increases risk over a de novo procedure.

The interventional cardiologist also frequently faces challenges. Access may be limited (owing to peripheral vascular disease, vessel tortuosity); contrast-induced nephropathy is a constant concern; and small, calcified, tortuous, diffusely diseased coronary vessels are common. The cardiothoracic surgeon faces diastolic dysfunction disproportionate to the degree of systolic dysfunction, atherothrombotic aortic disease (including “egg-shell” aortas, ulcerated plaques, and atherothrombotic debris), a paucity of vessels to provide good graft material, and limited targets suitable for revascularization (including the armor-coated vessel, given the enthusiasm for reconstructive stenting).

The Trial of Invasive versus Medical therapy in the Elderly with symptomatic CAD (TIME) reported by Jeger and Pfisterer compared medical and revascularization strategies in patients 75 years or older without other major life-limiting co­morbidity who were candidates for both medical and revascularization strategies. The preplanned analysis of the subgroup of patients with a history of diabetes and/or receiving treatment with antidiabetic drugs includes 69 patients (23% of the overall group), of whom 18 (26%) were receiving insulin. Analysis was by treatment received rather than by intention-to-treat. Baseline characteristics, symptoms, and quality of life are reported and compared between diabetic and nondiabetic groups, but not for the diabetic cohorts treated with medical therapy versus revascularization. Cor­onary angiography was performed in all patients considered for revascularization; extent of coronary disease and severity is not known for the patients randomized to and treated with medical therapy. The details of medical optimization in the patients randomized to medical therapy are not provided. Revascularization (CABG in 16 patients and PCI in 30) in the diabetic cohort was performed by treatment assignment in 62% and in 41% for medically refractory angina in the first year of follow-up. The method of revascularization was based on “clinical, angiographic, and feasibility judg­ments.” Revascularization de­­tails (angioplasty—balloon/bare-metal, or drug-eluting stent; CABG—number and type of grafts; for both—completeness and complications of revascularization) are not provided. There was a trend toward significant im­provement in long-term survival in diabetic patients with revascularization (74% versus 52%; P = .07). The long-term mortality rates for revascularization with PCI and CABG were not significantly different (25% versus 43%), though severity of angina and antianginal drug use were significantly less in the CABG surgery patients.

How should this study be incorporated into our current practice? The study supports the current practice of considering revascularization in elderly diabetic patients with medically refractory angina and without life-limiting comorbidity. Despite increased mortality in patients with diabetes, revascularization may improve quality of life and survival over medical therapy alone in appropriately selected patients. The decision to offer revascularization to the elderly diabetic patient must be carefully individualized based on cardiac findings, the overall medical condition, and comorbidity, quality of life, and treatment objectives. While the extent and severity of CAD and severity of left ventricular dysfunction remain important prognostically, treatment recommendations need to be based on more than cardiac considerations in elderly patients with diabetes.