Commentary
High Resting Heart Rate May Signal Exacerbation Risk in COPD Patients
Doug Brunk
Frontline Medical News
Higher resting heart rate (HR) may predict future risk of exacerbation in patients with recent chronic obstructive pulmonary disease (COPD) exacerbation, results from a multicenter study suggest.
“Resting heart [rate] is often...readily available clinical data,” lead study author Ahmad Ismail, MD, said in an interview in advance of the annual meeting of the American College of Chest Physicians. “Its significance is often overlooked in daily clinical practice until tachycardia or bradycardia happens. In COPD patients, it has been shown that the resting HR can predict mortality. However, there is a lack of data showing its association with the rates of exacerbations, the major player in determining overall outcome in patients with COPD.”
In an effort to identify the association between resting HR and risk of exacerbations, Dr Ismail of Universiti Teknologi MARA, Malaysia, and his associates at nine other centers evaluated 147 COPD patients who were recruited during acute exacerbation of COPD that required hospitalization between April 2012 and September 2015. The researchers recorded each patient’s sociodemographic data, anthropometric indices, and medication history during their acute exacerbation at the hospital. Next, they followed up with the patients in clinic at 3 months after the recruitment (month 0), and collected resting HR, spirometry, and COPD Assessment Test (CAT) scores. Subsequently, patients were followed up in clinic at 6 and 12 months, and followed up in between via telephone interviews to collect data on exacerbation history.
The mean age of the study population was 67 years, and 77% had higher resting HR, defined as exceeding 80 beats/min (bpm). The mean resting HR in the higher resting HR group was 92 bpm, compared with a mean of 70 bpm in the lower resting HR group. Dr Ismail reported that at month 3, patients with higher resting HR had a significantly higher proportion of exacerbations, compared with those who had a lower resting HR (54% vs 27%; P = .013). The trend was followed through until month 9. There was also a statistically significant moderate strength linear correlation between resting HR and exacerbation frequency at 3, 6, and 9 months (r = 0.400, P < .001; r = 0.440, P < .001; and r = 0.416, P = .004, respectively). The mean exacerbation frequency was also significantly higher in the higher resting HR group at month 3 and month 6 (2.00 vs 0.48, P < .001; and 3.42 vs 1.14, P = .004).
“Higher resting heart rate may predict future risk of exacerbation in patients with recent COPD exacerbation,” Dr Ismail concluded. “Further study however is required to determine the effect of lowering resting heart rate on the future risk of exacerbation.” He acknowledged certain limitations of the study, including the fact that it excluded patients who were on beta-blockers or any rate-modifying drugs, and those with history of cardiac failure and ischemic heart disease, and that there was no baseline echocardiogram performed to ensure the absence of ischemic heart disease and other possible causes of the higher resting HR. “We also had slightly higher than expected dropouts giving a nonsignificant result at 12 months follow-up, though the trend follows the overall results of the study,” he said.