Queuing for coronary angiography during severe supply-demand mismatch in aUS public hospital - Analysis of a waiting list registry

Context Adverse cardiac events have been reported in patients waiting for e ither coronary surgery or angioplasty. However, data on the risk of adverse events while awaiting coronary angiography are limited, and none are avail able from a US population. Objective To quantify cardiac outcomes in patients waiting for elective cor onary angiography. Design, Setting, and Participants Observational cohort study of 381 adult o utpatients (mean [SD] age, 55 [12] years; 64% male; 61% white) on a waiting list for coronary angiography at a US tertiary care public teaching hospit al during 1993-1994. Main Outcome Measures Rates of cardiac death, nonfatal myocardial infarctio n, and hospitalizations for unstable angina or heart failure as a function of amount of time spent on a waiting list. Results Sixty-six patients were dropped from the waiting list but were incl uded in the study analysis. During a mean (SD) follow-up of 8.4 (6.5) month s, cardiac death, myocardial infarction, and hospitalization occurred in 6 (1.6%), 4 (1.0%), and 26 (6.8%) patients, respectively. The probability of events was minimal in the first 2 weeks and increased steadily between 3 an d 13 weeks. By Cox multivariate analysis, 2 variables independently identif ied an increased risk of adverse events: a strongly positive treadmill exer cise electrocardiogram or positive stress imaging result at referral (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.22-4.16; P=.01) and the u se of 2 to 3 anti-ischemic medications (OR, 1.98; 95% CI, 1.19-3.96; P=.04) . Among 311 patients who ultimately underwent angiography, those with adver se events had a higher prevalence of coronary disease (96% vs 60%; P<.001), more frequently required revascularization (93% vs 53%; P<.001), and had l onger hospital stays (mean [SD], 6.2 [4.3] vs 1.3 [0.7] days; P=.001). Conclusion Our data suggest that in a cohort referred for coronary angiogra phy, delaying the procedure places some patients at risk for death, myocard ial infarction, unplanned hospitalization, a longer hospital stay, and, pot entially, a poorer prognosis. Waits longer than 2 weeks should be avoided, and patients with strongly positive stress test results and those who requi re 2 to 3 anti-ischemic medications should be prioritized for early interve ntion.