Survival improved with normalized heart rate recovery after cardiac rehabilitation
MedWire News: Patients with abnormal heart rate recovery (HRR) that is normalized after cardiac rehabilitation (CR) have an improved chance of long-term survival, study findings show.
Cardiac rehabilitation is the most underused treatment in the USA and not enough doctors recommend it to their patients, noted lead author Leslie Cho (Cleveland Clinic, Ohio, USA) in a press statement.
The team evaluated the HRR and mortality rate of 1070 consecutive patients who underwent exercise stress testing before and after completion of a CR program, over a median follow-up period of 8 years.
The 12-week program comprised an average of three physician-supervised exercise sessions per week. During these sessions patients participated in 10-15 minutes of warm-up and stretching, 30-50 min of continuous aerobic activity, and 15-20 min of cool-down.
The findings, reported in the journal Circulation, showed that of the 544 patients with an abnormal HRR (defined as a difference of ≤12 beats between peak heart rate during exercise and 1 min into recovery), 225 (41%) had a normal HRR after rehabilitation (>12 beats).
Of the whole cohort, 197 (18%) patients died during follow-up. Patients who had an abnormal HRR at baseline that normalized after rehabilitation had a significantly higher survival rate than those who continued to have an abnormal HRR after rehabilitation (p<0.001).
Abnormal HRR at baseline and upon program completion individually predicted mortality, at hazard ratios [HR] of 2.27 and 3.34, respectively.
After adjusting for variables including smoking history, weight, and change in medication use, abnormal HRR at completion was still strongly predictive of death in all patients (HR=2.24), but baseline abnormal HRR was no longer a significant predictor.
Further analysis revealed that patients who had an abnormal HRR at baseline that normalized upon completion had a similar rate of survival to those who had a normal HRR at baseline and after rehabilitation.
Additional research is needed to determine whether continuing CR for an additional 12 weeks can bring heart rate recovery into the normal range for these patients, commented Cho.
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By Piriya Mahendra