AT CHEST 2016
LOS ANGELES (FRONTLINE MEDICAL NEWS) – Higher resting heart rate 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 a 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 heart rate 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 heart rate and risk of exacerbation, 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 heart rate, 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% of them had higher resting heart rates, defined as one that exceeded 80 beats per minute (BPM). The mean resting heart rate in the higher resting heart rate group was 92, compared with a mean of 70 BPM in the lower resting heart rate group. Dr. Ismail reported that at month 3, patients with higher resting heart rates had significantly higher proportion of exacerbations, compared with those who had a lower resting heart rates (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 heart rate and exacerbation frequency at 3, 6, and 9 months (r = 0.400; P less than .001: r = 0.440; P less than .001: and r = 0.416; P = .004, respectively). The mean exacerbation frequency was also significantly higher in the higher resting heart rate group at month 3 and month 6 (2.00 vs. 0.48; P less than .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 heart rates. “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.
The study was funded by a grant from the Malaysian Thoracic Society. Dr. Ismail reported having no financial disclosures.