PRomPT: Peri-infarct pacing does not prevent LV remodeling, improve outcomes

LONDON — Peri-infarct pacing did not prevent left ventricular remodeling or improve outcomes during 18 months of follow-up in patients with large first MI, according to data from the PRomPT study.

Gregg W. Stone, MD, reported data on 126 patients at 27 sites within 10 days of onset of anterior or nonanterior MI (creatine phosphokinase > 3,000 U/L and QRS duration ≤ 120 ms). The patients were randomly assigned in a 1:1:1 ratio to dual-site biventricular pacing or single-site LV pacing using a cardiac resynchronization therapy defibrillator device with LV and RV leads (Protecta XT or Consulta, Medtronic) or no implantation (control group).

Gregg W. Stone

The primary endpoint was change in LV end-diastolic volume from baseline to 18 months, as assessed by the echocardiography core laboratory.

According to results presented here and published in European Heart Journal, change in LV end-diastolic volume increased by 15.3 ± 28.6 mL in the control group vs. 16.7 ± 30.5 mL in the pooled pacing groups during follow-up (adjusted mean difference, 0.6 mL; P = .92). This finding did not differ between patients assigned single- or dual-site pacing.

“The difference was negligible and there was no significant difference in this outcome,” Stone, professor of medicine at Columbia University, director of cardiovascular research and education at Columbia University Medical Center/New York-Presbyterian Hospital, co-director of medical research and education at the Cardiovascular Research Foundation and Cardiology Today’s Intervention Editorial Board member, said during a press conference.

The data also demonstrated no significant differences in change in LV end-systolic volume (pooled pacing, 11.4 ± 24.6 mL; control, 13.8 ± 26.1; adjusted mean change, –2.8 mL; P = .61) or ejection fraction (pooled pacing, –0.6 ± 8.6%; control, –3.3 ± 9.1%; adjusted mean change, 2.3; P = .2) from baseline to 18 months between the groups.

Changes in quality of life, as indicated by responses to the Minnesota Living with Heart Failure questionnaire (adjusted mean change: pooled pacing, 0.4; control, –0.1; P = .92) and the European Quality of Life-5 Dimension questionnaire (adjusted mean change: pooled pacing, 0.1; control, 0.1; P = .99), were similar.

Among 101 patients with serial assessments, NYHA HF class improved in 37.6%, was unchanged in 43.6% and worsened in 18.8% during 18 months. This finding did not differ between the pooled pacing or control groups.

Improvements in 6-minute walk distance results were similar between the groups (adjusted mean change: pooled pacing, 37.6 m; control, 15.6 m; P = .45). However, the improvement in walking distance was greater among patients with single-site pacing vs. dual-site pacing.

Stone noted that this was a “high-risk” population. More than 45% were hospitalized within 18 months of follow-up. Results showed no significant differences in rates of freedom from death or HF hospitalization at 18 months between the pooled pacing and control groups (pooled pacing, 82.6 vs. control, 78.3; HR = 0.79; 95% CI, 0.34-1.86).

However, the researchers “cannot exclude a possible benefit [of peri-infarct pacing] in some subgroups, for which the trial was underpowered to detect,” Stone said during a presentation. – by Katie Kalvaitis

References:

Stone GW, et al. Hot Line I: Acute Myocardial Infarction. Presented at: European Society of Cardiology Congress; Aug. 29-Sept. 2, 2015; London.

Stone GW, et al. Eur Heart J. 2015;doi:10.1093/eurheartj.ehv436.

Disclosure: The study was supported by Medtronic. Stone reports no relevant financial disclosures.