Faculty Collaboration Database

Reclassification of cardiovascular risk in patients with normal myocardial perfusion imaging using heart rate response to vasodilator stress. Am J Cardiol 2013 Jan 15;111(2):190-5

Date

11/01/2012

Pubmed ID

23111139

DOI

10.1016/j.amjcard.2012.09.013

Scopus ID

2-s2.0-84872024858 (requires institutional sign-in at Scopus site)   25 Citations

Abstract

Previous studies have shown that patients with normal vasodilator myocardial perfusion imaging (MPI) findings remain at a greater risk of future cardiac events than patients with normal exercise MPI findings. The aim was to assess improvement in risk classification provided by the heart rate response (HRR) in patients with normal vasodilator MPI findings when added to traditional risk stratification. We retrospectively studied 2,000 patients with normal regadenoson or adenosine MPI findings. Risk stratification was performed using Adult Treatment Panel III framework. Patients were stratified by HRR (percentage of increase from baseline) into tertiles specific to each vasodilator. All-cause mortality and cardiac death/nonfatal myocardial infarction (MI) ≤2 years from the index MPI were recorded. During follow-up, 11.8% patients died and 2.7% patients experienced cardiac death/nonfatal MI in the adenosine and regadenoson groups, respectively. The patients who died had a greater Framingham risk score (12 ± 4 vs 11 ± 4, p = 0.009) and lower HRR (22 ± 16 vs 32 ± 21, p <0.0001). In an adjusted Cox model, the lowest tertile HRR was associated with an increased risk of mortality (hazard ratio 2.1) and cardiac death/nonfatal MI (hazard ratio 2.9; p <0.01). Patients in the highest HRR tertile, irrespective of the Adult Treatment Panel III category, were at low risk. When added to the Adult Treatment Panel III categories, the HRR resulted in net reclassification improvement in mortality of 18% and cardiac death/nonfatal MI of 22%. In conclusion, a blunted HRR to vasodilator stress was independently associated with an increased risk of cardiac events and overall mortality in patients with normal vasodilator MPI findings. The HRR correctly reclassified a substantial proportion of these patients in addition to the traditional risk classification models and identified patients with normal vasodilator MPI findings, who had a truly low risk of events.

Author List

Iqbal FM, Al Jaroudi W, Sanam K, Sweeney A, Heo J, Iskandrian AE, Hage FG

Author

Fahad M. Iqbal MD Staff Physician in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adenosine
Alabama
Cardiovascular Diseases
Exercise Test
Female
Heart Rate
Humans
Incidence
Male
Middle Aged
Myocardial Perfusion Imaging
Prognosis
Proportional Hazards Models
Retrospective Studies
Risk Assessment
Risk Factors
Vasodilator Agents