Background / Aims

Heart failure with preserved ejection fraction (HFpEF) is a common condition related to increased morbidity and mortality with only very few effective therapeutic options. Only recently, the concept to create an interatrial shunt to decompress elevated left atrial pressure, led to the advent of interatrial-shunt-devices (IASD). So far, randomized controlled data attesting efficacy are lacking as do standardized screening protocols for this innovative therapy. Here, we aimed to estimate the symptomatic therapeutic benefit of IASD implantation in an all-comer cohort of persistent symptomatic HFpEF. Moreover, we evaluated the potential of standardized exercise hemodynamics (ExHemo) compared to resting hemodynamics (RestHemo) by right heart catheterization during IASD screening to effectively tailor IASD therapy.  

Methods

We present 27 all-comer patients qualified for IASD implantation according to RestHemo measurements in two advanced heart failure units in 2020/2021. Due to restricted availability of a bike-exercise platform, only sixteen patients underwent ExHemo testing. Primary endpoint was a change in overall well-being after IASD implantation. Overall well-being was subjectively self-reported by the patient and scaled by school grades (1=very good, 6=insufficient). A responder was defined as an improvement in self-reported well-being (≥1). Secondary endpoint was the change in NYHA classification.

Results

All 15 RestHemo patients received IASD implantation. In the ExHemo group, we abstained from IASD implantation in 6 out of 12 patients that fulfilled implantation criteria at rest but exhibited abnormalities during exercise right-heart catheterization (e.g. right heart failure), thus leading to 6 IASD implants in the ExHemo group.

At the time of survey, duration of IASD implantation dated back 184 ± 110 days in ExHemo and 401 ± 228 days in the RestHemo group (*p=0.04). Results of resting right heart catheterization did not differ between the groups (Pc 20.4 ± 4.5 mmHg versus 19.7 ± 5.5 mmHg, p=0.85, RA 9.3 ± 3.3 mmHg +10.8 ± 4.3 mmHg, p=0.42)). Similarly, baseline characteristics did not differ in terms of age, gender, prevalence of atrial fibrillation, renal function, NYHA class, heart failure medications or H₂FPEF Score (RestHemo vs. ExHemo 6.9±1.9 vs. 5.5±1.6; p=0.15 ). Right ventricular end-diastolic diameter) was higher in the RestHemo group (38.0±4.4 mm versus 30.0±3.3, p=0.04).

There was no difference in quantitative self- assessment prior IASD implantation (RestHemo: 5.0±1.0 vs. ExHemo: 5.5±0.5; p=0.23). Following IASD implantation, there were significantly more responders in the ExHemo (6 (100%) versus 8 (53%), p=0.04).

ExHemo resulted in better subjective global assessment (ExHemo: 3.5±1.2 vs. RestHemo: 2.3±0.5; p=0.03). Absolute subjective improvement compared to pre IASD implantation was more pronounced in the ExHemo group (ExHemo: ∆3.2±0.7 vs. RestHemo: ∆1.5±1.8, p=0.02). In line with subjective global assessment NYHA class revealed less heart failure symptoms in the ExHemo group following IASD implantation (ExHemo: 1.5±0.5vs. RestHemo: 2.6±0.5; p<0.01).

Conclusion

IASD implantation appears as effective innovative therapy for persistent symptomatic HFpEF. Standardized exercise hemodynamic protocols for screening may help to improve tailoring this innovative therapy to responders.