Objectives
The DANHEART trial is a multicenter, randomized (1:1), parallel-group, double-blind, placebo-controlled study in chronic heart failure patients with reduced ejection fraction (HFrEF). This investigator driven study will include 1500 HFrEF patients and test in a 2 x 2 factorial design: 1) if hydralazine-isosorbide dinitrate reduces the incidence of death and hospitalization with worsening heart failure vs. placebo (H-HeFT) and 2) if metformin reduces the incidence of death, worsening heart failure, acute myocardial infarction, and stroke vs. placebo in patients with diabetes or prediabetes (Met-HeFT).
Methods
Symptomatic, optimally treated HFrEF patients with LVEF ≤40% are randomized to active vs. placebo treatment. Patients can be randomized in either both H-HeFT and Met-HeFT or to only one of these study arms. In this event-driven study, it is anticipated that 1300 patients should be included in H-HeFT and 1100 in Met-HeFT and followed for an average of 4 years.
Results
As of May 2020, 296 patients have been randomized at 20 centers in Denmark.
Conclusion
The H-HeFT and Met-HeFT studies will yield new knowledge about the potential benefit and safety of two commonly prescribed drugs with limited randomized data in patients with HFrEF.
Prospective studies applying fluoroscopy for assessment of right ventricular (RV) lead position have failed to show clear benefits from RV septal pacing. We investigated the impact of different RV lead positions verified by computed tomography (CT) on the risk of pacing-induced cardiomyopathy (PICM). We retrospectively included 153 patients who underwent routine fluoroscopy-guided pacemaker implantation between March 2012 and May 2020. All patients had normal pre-implant left ventricular ejection fraction (LVEF). Patients attended a follow-up visit including contrast-enhanced cardiac CT and transthoracic echocardiography. Patients were classified as septal or non-septal based on CT analysis. The primary endpoint was PICM (LVEF < 50% with ≥10% decrease after implantation). Based on CT, 48 (31.4%) leads were septal and 105 (68.6%) were non-septal. Over a median follow-up of 3.1 years, 16 patients (33.3%) in the septal group developed PICM compared to 31 (29.5%) in the non-septal group (p = 0.6). Overall, 13.1% deteriorated to LVEF ≤ 40%, 5.9% were upgraded to cardiac resynchronization therapy device, and 14.4% developed new-onset atrial fibrillation, with no significant differences between the groups. This study demonstrated a high risk of PICM despite normal pre-implant left ventricular systolic function with no significant difference between CT-verified RV septal or non-septal lead position.
Background
Right ventricular (RV) pacing may induce significant left ventricular (LV) dyssynchrony resulting in pacing-induced cardiomyopathy (PICM). LV activation sequence is affected by RV pacing site and previous studies suggest that RV septal pacing may be superior compared to traditional RV apical pacing. However, results are conflicting and randomized controlled trials have failed to show clear benefits from RV septal pacing. Traditionally, studies have applied fluoroscopy to determine RV lead implantation site. However, locating pacing site using this method is known to be inaccurate and poorly reproducible compared with cardiac computed tomography (CT). The purpose of our study was to evaluate the association between RV pacing site determined by cardiac CT and risk of PICM.
Methods
We retrospectively included 153 patients with pre-implant LV ejection fraction (LVEF) ≥50% who underwent fluoroscopy-guided dual chamber pacemaker implantation due to high-degree atrioventricular block between March 2012 and May 2020. All patients attended a follow-up visit including cardiac CT and transthoracic echocardiography. RV lead position was evaluated from CT dividing the RV into three segments: apical, septum or free wall (Figure 1). Furthermore, RV lead position estimated by the implanting physician, using fluoroscopy during pacemaker implantation, was retrieved from medical records. The primary endpoint was PICM defined as ≥10% decrease in LVEF from time of pacemaker implantation to follow-up, resulting in LVEF <50%.
Results
Mean duration of follow-up was 3.7 years (range 2.1–8.7). The implanting physician estimated 131 (85.6%) leads to be located septal, 5 (3.3%) located non-septal and 17 (11.1%) were unknown. Based on CT, 48 (31.4%) leads were located septal and 105 (68.6%) were located non-septal of which 31 were located on the free wall (20.4%). With CT as the golden standard, 47 (35%) leads were estimated correctly during fluoroscopy-guided implantation. No significant differences between patient characteristics in the CT-estimated septal and non-septal groups were observed except for ischemic heart disease (P=0.05) (Table 1). There were 16 (33.3%) patients in the septal group who developed PICM compared to 31 (29.5%) in the non-septal group (P=0.6). Adjusting for ischemic heart disease did not change this result. In the septal group, the change in LVEF from baseline to follow-up was −9.0±10.4% compared to −7.5±9.1% in the non-septal group (P=0.4).
Conclusion
In total 31% developed PICM despite having a normal pre-implant LVEF with no observed difference between RV septal and non-septal pacing. With CT as the golden standard, RV leads were inaccurately located during fluoroscopy-guided pacemaker implantation with only 35% being located correctly. Misclassification of pacing sites in previous studies may have contributed to the inconsistent results.
Funding Acknowledgement
Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Svend Andersens FondKarl G Andersens Fond
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