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. 2022 Sep 15;12(9):1512.
doi: 10.3390/jpm12091512.

The Interplay of PR Interval and AV Pacing Delays Used for Cardiac Resynchronization Therapy in Heart Failure Patients: Association with Clinical Response in a Retrospective Analysis of a Large Observational Study

Maurizio Gasparini  1 , Mauro Biffi  2 , Maurizio Landolina  3 , Giuseppe Cattafi  4 , Roberto Rordorf  5 , Giovanni Luca Botto  6 , Giovanni Battista Forleo  7 , Giovanni Morani  8 , Luca Santini  9 , Antonio Dello Russo  10 , Antonio Rossillo  11 , Sarah Meloni  12 , Andrea Grammatico  12   13 , Marco Vitolo  14   15 , Giuseppe Boriani  14
Affiliations

The Interplay of PR Interval and AV Pacing Delays Used for Cardiac Resynchronization Therapy in Heart Failure Patients: Association with Clinical Response in a Retrospective Analysis of a Large Observational Study

Maurizio Gasparini et al. J Pers Med. .

Abstract

Background. Cardiac resynchronization therapy (CRT) is a treatment for heart failure (HF) patients with prolonged QRS and impaired left ventricular (LV) systolic function. We aim to evaluate how the baseline PR interval is associated with outcomes (all-cause death or HF hospitalizations) and LV reverse remodeling (>15% relative reduction in LV end-systolic volume). Methods. Among 2224 patients with CRT defibrillators, 1718 (77.2%) had a device programmed at out-of-the-box settings (sensed AV delay: 100 ms and paced AV delay: 130 ms). Results. In this cohort of 1718 patients (78.7% men, mean age 66 years, 71.6% in NYHA class III/IV, LVEF = 27 ± 6%), echocardiographic assessment at 6-month follow-up showed that LV reverse remodeling was not constant as a function of the PR interval; in detail, it occurred in 56.4% of all patients but was more frequent (76.6%) in patients with a PR interval of 160 ms. In a median follow-up of 20 months, the endpoint of death or HF hospitalizations occurred in 304/1718 (17.7%) patients; in the multivariable regression analysis it was significantly less frequent when the PR interval was between 150 and 170 ms (hazard ratio = 0.79, 95% confidence interval (CI): 0.63−0.99, p = 0.046). The same PR range was associated with higher probability of CRT response (odds ratio = 2.51, 95% CI: 1.41−4.47, p = 0.002). Conclusions. In a large population of CRT patients, with fixed AV pacing delays, specific PR intervals are associated with significant benefits in terms of LV reverse remodeling and lower morbidity. These observational data suggest the importance of optimizing pacing programming as a function of the PR interval to maximize CRT response and patient outcome.

Keywords: atrioventricular conduction; cardiac resynchronization therapy; death; heart failure; pacing; programming.

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Conflict of interest statement

M.L. has received lecture fees from Boston Scientific, LivaNova, Medtronic, Boehringer Ingelheim, Bayer and Pfizer. G.B. reported speaker’s fees from Bayer, Boehringer Ingelheim, Boston, Daiichi-Sankyo, Janssen. L.S. reported speaker’s fees from Boehringer Ingelheim, Boston, Medtronic, Abbott and advisory services for Abbott, Boston Scientific and Dompè. A.R. reported speaker’s fees from Boehringer Ingelheim, Daiichi Sankyo, Pfizer and Consultant’s fee from Abbott. S.M. is a Medtronic employee. A.G. was a Medtronic employee and currently is an Abbott employee. The other authors have no conflicts of interest or relationships with industries to disclose.

Figures

Figure 1
Figure 1
CRT response as a function of the PR interval in all patients.
Figure 2
Figure 2
CRT response as a function of the PR interval according to QRS morphology.
Figure 3
Figure 3
Incidence of atrial fibrillation longer than 7 days as a function of the PR interval.
See this image and copyright information in PMC

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