Author + information
Diabetes mellitus (DM) and chronotropic incompetence, measured by % heart rate (HR) reserve achieved (%HRR), are predictors of all-cause mortality (ACM). We studied the prognostic relationship between DM and %HRR in patients (pts) undergoing exercise myocardial perfusion SPECT (MPS).
12,291 consecutive pts not on β blockers underwent symptom-limited exercise MPS. %HRR was defined as (peak HR – rest HR) × 100/ (220-age-rest HR), with < 80% defined as low. Cox proportional hazard analysis was used for survival modeling.
519 ACM deaths occurred during a follow-up of 1182 + 827 days. Of 12,291 pts, 1,423 (11.6%) had DM and 3,579 (29.1%) had low %HRR. Pts with DM were more likely to have a low %HRR (45% vs. 27%, p<0.001). After adjusting for age, sex, family history of CAD, symptom, exercise duration, and MPS defect extent and severity, %HRR and DM were predictive of ACM death. Adjusted survival stratified by %HRR and DM is shown in the Figure. In pts with either %HRR <80% or DM, the risk was almost identical (Hazard Ratio=1.7; confidence interval (CI) 1.4-2.1 vs. 1.7, CI 1.2-2.3). In pts with %HRR <80% and DM the risk was higher (Hazard Ratio=2.3, CI 1.8-3.1).
The presence of impaired heart rate response may be equivalent to diabetes as a predictor of all-cause mortality, and the presence of both is additive prognostically.
Poster Sessions, Expo North
Monday, March 11, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Prognostic Implications in Nuclear Imaging
Abstract Category: 21. Imaging: Nuclear
Presentation Number: 1315-361
- 2013 American College of Cardiology Foundation