CRT may improve sleep apnea in pacing-induced cardiomyopathy
Central sleep apnea was common in patients with pacing-induced cardiomyopathy and may improve with cardiac resynchronization therapy compared with right ventricular pacing, researchers found in the UPGRADE trial.
“The main findings are new, as pacing-induced cardiomyopathy is so far poorly studied,” Wolfgang Dichtl, MD, PhD, assistant medical director of University Clinic of Internal Medicine III at Medical University Innsbruck in Austria, told Healio. “In fact, this is the first published work showing the positive effects of upgrading to CRT concerning structural improvement (increase in left ventricular ejection fraction and decrease in left ventricular systolic volumes) and decrease in biomarkers (N-terminal-pro-B-type natriuretic peptide plasma levels) in a randomized trial.”
Patients undergoing LV lead implantation
In the randomized controlled, prospective trial published in The American Journal of Cardiology, Fabian Barbieri, MD, clinical cardiologist at Medical University Innsbruck in Austria, and researchers analyzed data from 54 patients (median age, 75 years; 80% men) with pacing-induced cardiomyopathy who underwent LV lead implantation within the past month.
Single-night polysomnography determined whether patients had central sleep apnea (n = 27; median age, 75 years; 90% men), obstructive sleep apnea (n = 16; median age, 75 years; 81% men) or no sleep apnea (n = 11; median age, 74 years; 55% men).
Patients with moderate or severe central sleep apnea (n = 22) were assigned CRT or RV pacing. Follow-up was conducted at 3 to 5 months, when patients underwent another single-night polysomnography. Patients were then crossed over and rescheduled for another follow-up single-night polysomnography within 3 to 5 months.
Patients assigned CRT had an increase in LVEF (31% to 45%; P < .001) compared with RV pacing. These patients also had reductions in LV end systolic volumes (144 mL to 108 mL; P < .001) and NT-proBNP plasma levels (2,343 ng/L to 1,282 ng/L; P < .001). Significant effects were not observed with ongoing RV pacing.
After 3.9 months of CRT, central sleep apnea improved, as shown by decreases in the apnea hypopnea index (39.1 events per hour to 22.2 events per hour; P < .001) and central apnea index (27.1 events per hour to 6.8 events per hour; P < .001). RV pacing minorly improved the apnea-hypopnea index and the central apnea index.
Preexisting central sleep apnea had no effect on the structural response rate and midterm follow-up at a median of 2.8 years.
‘Marker of poor prognosis’
“Sleep apnea is rather a marker of poor prognosis in heart failure patients and not a target per se for intervention,” Dichtl said in an interview. “This has been shown for adaptive servo-ventilation in central sleep apnea in the large SERVE-HF trial. [The] UPGRADE [trial] points in this direction as well, but the study design does not allow to separate the positive effects of CRT on central sleep apnea and clinical outcome.”
For more information:
Wolfgang Dichtl, MD, PhD, can be reached at email@example.com.