Early right ventricular response to cardiac resynchronization therapy: impact on clinical outcomes

Early response of right-ventricular function to percutaneous mitral valve repair

Background

The change in right-ventricular function (RVF) after transcatheter mitral valve repair is still poorly understood. We assessed the early response of RVF to the MitraClip procedure and its clinical relevance.

Methods

We analyzed consecutive patients who underwent a MitraClip procedure to treat MR between August 2010 and March 2019 in the Heart Failure Network Rhineland registry. RVF was assessed before and after the procedure. Impaired RVF was defined as an RV fractional area change (RVFAC) < 35% or tricuspid annular plane systolic excursion (TAPSE) < 16 mm.

Results

816 eligible patients (77 ± 9 years, 58.5% male) were included in the analysis. Baseline values of RVF were: RVFAC 38.6 (IQR 29.7–46.7) % and TAPSE 17.0 (IQR 14.0–21.0) mm. At a median time of 3 (IQR 2–5) days after the procedure, the RVF remained normal in 34% (n = 274), normalized in 17% (n = 140), deteriorated in 15% (n = 125), and was persistently impaired in 34% (n = 277) of patients. The RVF response was significantly associated with a composite outcome of all-cause mortality and hospitalization due to heart failure within a 2-year follow-up. Compared to stable/normal RVF, the adjusted hazard ratios for the outcome were 1.78 (95% CI 1.10–2.86) for normalized RVF, 1.89 (95% CI 1.34–3.15) for deteriorated RVF, and 2.25 (95% CI 1.47–3.44) for persistently impaired RVF. Changes in TAPSE and RVFAC as continuous variables were significantly correlated with the outcome.

Conclusion

An early change in RVF following transcatheter mitral valve repair is predictive of mortality and hospitalization due to heart failure during follow-up.

Graphic abstract

Early response of RVF after MitraClip and its clinical significance. An acute, early change in RVF can be observed following the MitraClip procedure, which is associated with the risk of mortality and hospitalization for HF.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01951-7.

Impact on clinical outcomes of right ventricular response to percutaneous correction of secondary mitral regurgitation

AIMS

In patients with heart failure and reduced ejection fraction (HFrEF) and secondary mitral regurgitation (SMR), impaired right ventricular function (RVF) may negatively influence the prognosis. Percutaneous mitral valve repair (pMVR) can promote the recovery of RVF. We sought to characterize the response of the right ventricle to pMVR in HFrEF with SMR and to assess the association between improved RVF after pMVR and outcomes.

METHODS AND RESULTS

Overall, 221 patients with HFrEF and SMR ≥3+ successfully treated with pMVR in four tertiary care centres for heart failure were included. Improved RVF was defined as Δ right ventricular fractional area change (ΔRVFAC) ≥5% at early follow-up (median time 4 months). The primary endpoint was a composite of death/heart transplantation (D/HT). Mean age was 69 ± 11 years, mean left ventricular ejection fraction was 31 ± 8% and mean RVFAC was 34 ± 9%. ΔRVFAC ≥5% occurred in 88 patients (40%) and was independent of the measures of left ventricular reverse remodelling. During a median follow-up of 29 months (interquartile range 12-46), 81 patients (37%) reached the primary endpoint. After adjustment for other significant covariates, ΔRVFAC ≥5% was significantly associated with lower risk of D/HT (hazard ratio 0.52, 95% confidence interval 0.29-0.94, P = 0.030). In the secondary outcome analysis exploring the risk of heart failure hospitalizations, ΔRVFAC ≥5% confirmed the prognostic association with the endpoint.

CONCLUSIONS

In patients with HFrEF and SMR, about 40% of patients improved RVF after pMVR. RVF improvement was associated with better long-term survival free from HT and lower risk of heart failure hospitalization.

Cardiac fluid dynamics meets deformation imaging

Cardiac function is about creating and sustaining blood in motion. This is achieved through a proper sequence of myocardial deformation whose final goal is that of creating flow. Deformation imaging provided valuable contributions to understanding cardiac mechanics; more recently, several studies evidenced the existence of an intimate relationship between cardiac function and intra-ventricular fluid dynamics. This paper summarizes the recent advances in cardiac flow evaluations, highlighting its relationship with heart wall mechanics assessed through the newest techniques of deformation imaging and finally providing an opinion of the most promising clinical perspectives of this emerging field. It will be shown how fluid dynamics can integrate volumetric and deformation assessments to provide a further level of knowledge of cardiac mechanics.

Prognostic significance of improvement in right ventricular systolic function during cardiac resynchronization therapy

Objectives There is conflicting evidence concerning the role of right ventricular (RV) systolic dysfunction in the long-term clinical outcome after cardiac resynchronization therapy (CRT). Therefore we aimed to assess evolution of RV systolic function during CRT, covariates associated with its improvement, and its impact on outcome. Methods and results All CRT device implantations (Jan 2009-Dec 2011) in our institution were reviewed. Records of 69 patients (25% female, mean age 62.8 ± 9.2 years, mean left ventricular (LV) ejection fraction 27 ± 8%) were analyzed. Baseline RV fractional area change (FAC) < 35% was present in 37 patients (54%). At one year, 24 of them (65%) improved in RV FAC. LV remodeling and mitral regurgitation were significantly associated with the likelihood of RV FAC improvement (OR 4.80, 95% CI 1.13-20.46, P = 0.034 and OR 0.32, 95% CI 0.12-0.89, P = 0.029, respectively). The composite endpoint of death or heart transplantation occurred in 23 patients (33%) over a mean follow-up of 2.8 ± 1.4 years. RV FAC at one year (HR 0.90, 95% CI 0.86-0.94, P < .001) was, independently of NYHA class and LV remodeling, associated with clinical outcome. Conclusions RV systolic function might improve during CRT. This seems mainly due to changed left-sided hemodynamics and LV remodeling. Good RV systolic function is independently related with better outcome.

Right heart-pulmonary circulation unit and cardiac resynchronization therapy

Clinical response to cardiac resynchronization therapy (CRT) has been known for years to be highly variable, with a spectrum of responses from no change or even deterioration of cardiac function to spectacular improvements. In the plethora of clinical, echocardiographic, biohumoral, and electrophysiological predictors of response to CRT and postimplant issues besides patient selection, the role of right ventricular (RV) function has been largely overlooked. In reviewing current evidence, we noticed conflicting results between observational studies and randomized trials not only concerning the impact of baseline RV function on CRT efficacy but also on the effects of CRT on RV size and function. Hence, we aimed to provide a critical reappraisal of current knowledge and unresolved issues on the reciprocal interactions between RV function and CRT, shifting the spotlight on the concept of right heart pulmonary circulation unit and on the clinical and prognostic significance of impaired ventricular-arterial coupling reserve. In this viewpoint, we propose that (1) CRT should not be denied to potential candidate because of "isolated" RV dysfunction and (2) assessment of baseline right heart pulmonary circulation unit and its dynamic response to pharmacological stress should be considered in future studies, as well as in the preimplant evaluation of individual candidates among other clinical factors.