Prognosis in patients with suspected or known ischemic heart disease and normal myocardial perfusion: Long-term outcome and temporal risk variations

Background: The prognostic value of a normal myocardial perfusion scintigraphy (MPS) may be well described, but long-term follow-up data are sparse, and temporal variations in risk are insufficiently elucidated. Methods and Results: During long-term follow-up (mean 6.2 years) of 1,327 consecutive Danish patients with normal MPS, the rate of all-cause death (ACD) was 1.9%/year (differing by gender) and of cardiac death (CD)/myocardial infarction (MI) 0.8%/year (differing by coronary artery disease, CAD). Female gender (HR: 0.60), age (HR: 1.07 per-year increment), and known CAD without prior revascularization (HR: 2.17) were statistically significant factors for ACD, whereas diabetes and previous MI per se were not. Known CAD with previous revascularization carried a low risk of ACD when adjusted for gender and age (HR: 0.56). For CD/MI, risk increased with age and threefold with known CAD, previous MI, and previous percutaneous coronary intervention. Judged from smoothed hazard functions, mortality risk increased further with time for men, elderly, and diabetics and markedly further with known CAD without prior revascularization. Conclusions: Following a normal MPS, rates of death and hard cardiac events were low. Risk varied with age, gender, and disease history. Novel aspects of temporal risk variation suggested a general warranty period of 5 years, but less in risk groups.