Relationship Between Reverse Remodeling and Cardiopulmonary Exercise Capacity in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

Peak exercise myocardial deformation indices during cardiopulmonary exercise testing are associated with exercise capacity and ventilatory efficiency in patients with dilated cardiomyopathy

OBJECTIVE

Little is known about the exercise-induced changes in the multidimensional mechanical properties of the heart. We aimed to evaluate the myocardial deformation indices (MDI) at rest and their response at peak exercise during the same cardiopulmonary exercise testing (CPET) session, investigating their relationship to exercise capacity and ventilatory sufficiency in dilated cardiomyopathy (DCM) patients.

METHODS

We evaluated left ventricular (LV) function using speckle tracking imaging (STI) at rest and peak exercise during the same CPET session in 57 idiopathic DCM patients in New York Heart Association (NYHA) I-II class [54 ± 12 years, 42 males, ejection fraction (EF) 33 ± 9%]. We measured global longitudinal strain (GLS), longitudinal strain rate at systole (LSRS) and diastole (LSRD), and circumferential strain rate (CircS).

RESULTS

Resting GLS, LSRS, and LSRD were impaired compared with the predicted values but were improved at peak exercise (p < 0.001). All MDI at rest and/or at peak exercise were related to several CPET-derived parameters, including peak VO₂, load, O₂ pulse, and VE/VCO₂ slope. Peak exercise LSRS > -1.10 sec^-1 (AUC = 0.80, p < 0.001) and GLS > -13% (AUC = 0.81, p = 0.002) predicted impaired exercise capacity (peak VO₂ < 20 ml/min/kg) and ventilatory inefficiency (VE/VCO₂ slope>34). In multiple regression analysis, peak exercise LSRS and GLS were independently related to the peak VO₂ (Beta = -0.39, p = 0.003) and VE/VCO₂ slope (Beta = 0.35, p = 0.02), respectively.

CONCLUSIONS

Peak exercise LSRS and GLS in NYHA I-II DCM patients subjected to CPET were associated with aerobic exercise capacity and ventilatory efficiency. Consequently, LSRS and GLS at peak exercise, through their association with CPET-derived CV risk indices, may underline the severity of heart failure and predict future CV events in this DCM population.

Does recovery from submaximal exercise predict response to cardiac resynchronisation therapy?

Background

Exercise parameters are not routinely incorporated in decision making for cardiac resynchronisation therapy (CRT). Submaximal exercise parameters better reflect daily functional capacity of heart failure patients than parameters measured at maximal exertion, and may therefore better predict response to CRT. We compared various exercise parameters, and sought to establish which best predict CRT response.

Methods

In 31 patients with chronic heart failure (61% male; age 68±7 years), submaximal and maximal cycling testing was performed before and 3 months after CRT. Submaximal oxygen onset (τVO₂ onset) and recovery kinetics (τVO₂ recovery), peak oxygen uptake (VO₂ peak) and oxygen uptake efficiency slope (OUES) where measured. Response was defined as ≥15% relative reduction in end-systolic volume.

Results

After controlling for age, New York Heart Association and VO₂ peak, fast submaximal VO₂ kinetics were significantly associated with response to CRT, measured either during onset or recovery of submaximal exercise (area under the curve, AUC=0.719 for both; p<0.05). By contrast, VO₂ peak (AUC=0.632; p=0.199) and OUES (AUC=0.577; p=0.469) were not associated with response. Among patients with fast onset and recovery kinetics, below 60 s, a significantly higher percentage of responders was observed (91% and 92% vs 43% and 40%, respectively).

Conclusions

Impaired VO₂ kinetics may serve as an objective marker of submaximal exercise capacity that is age-independently associated with non-response following CRT, whereas maximal exercise parameters are not. Assessment of VO₂ kinetics is feasible and easy to perform, but larger studies should confirm their clinical utility.

Predictors of sacubitril/valsartan high dose tolerability in a real world population with HFrEF

AIMS

The angiotensin receptor-neprilysin inhibitor (ARNI) sacubitril/valsartan (Sac/Val) demonstrated to be superior to enalapril in reducing hospitalizations, cardiovascular and all-cause mortality in patients with ambulatory heart failure and reduced ejection fraction (HFrEF), in particular when it is maximally up-titrated. Unfortunately, the target dose is achieved in less than 50% of HFrEF patients, thus undermining the beneficial effects on the outcomes. In this study, we aimed to evaluate the role of Sac/Val and its titration dose on reverse cardiac remodelling and determine which echocardiographic index best predicts the up-titration success.

METHODS AND RESULTS

From January 2020 to June 2021, we retrospectively identified 95 patients (65.6 [59.1-72.8] years; 15.8% females) with chronic HFrEF who were prescribed Sac/Val from the HF Clinics of 5 Italian University Hospitals and evaluated the tolerability of Sac/Val high dose (the ability of the patient to achieve and stably tolerate the maximum dose) as the primary endpoint in the cohort. We used a multivariable logistic regression analysis, with a stepwise backward selection method, to determine the independent predictors of Sac/Val maximum dose tolerability, using, as candidate predictors, only variables with a P-value < 0.1 in the univariate analyses. Candidate predictors identified for the multivariable backward logistic regression analysis were age, sex, body mass index (BMI), chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), dyslipidaemia, atrial fibrillation, systolic blood pressure (SBP), baseline tolerability of ACEi/ARBs maximum dose, left ventricle global longitudinal strain (LVgLS), LV ejection fraction (EF), tricuspid annulus plane systolic excursion (TAPSE), right ventricle (RV) fractional area change (FAC), RV global and free wall longitudinal strain (RVgLS and RV-FW-LS). After the multivariable analysis, only one categorical (ACEi/ARBs maximum dose at baseline) and three continuous (younger age, higher SBP, and higher TAPSE), resulted significantly associated with the study outcome variable with a strong discriminatory capacity (area under the curve 0.874, 95% confidence interval (CI) (0.794-0.954) to predict maximum Sac/Val dose tolerability.

CONCLUSIONS

Our study is the first to analyse the potential role of echocardiography and, in particular, of RV dysfunction, measured by TAPSE, in predicting Sac/Val maximum dose tolerability. Therefore, patients with RV dysfunction (baseline TAPSE <16 mm, in our cohort) might benefit from a different strategy to titrate Sac/Val, such as starting from the lowest dose and/or waiting for a more extended period of observation before attempting with the higher doses.

Cardiac remodelling - Part 2: Clinical, imaging and laboratory findings. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes. The remodelling process ultimately involves all cardiac chambers, but has been traditionally evaluated in terms of left ventricular volumes and ejection fraction. This is the second part of a review paper by the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology dedicated to ventricular remodelling. This document examines the proposed criteria to diagnose RR and AR, their prevalence and prognostic value, and the variables predicting remodelling in patients managed according to current guidelines. Much attention will be devoted to RR in patients with heart failure with reduced ejection fraction because most studies on cardiac remodelling focused on this setting.

Exercise-Based Cardiac Rehabilitation Improves Exercise Capacity Regardless of the Response to Cardiac Resynchronization Therapy in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

In patients with chronic heart failure with reduced ejection fraction (HFrEF), cardiac resynchronization therapy (CRT) improves left ventricular ejection fraction (LVEF) and exercise-based cardiac rehabilitation (ECR) enhances exercise capacity. This study examined the relationship between the 2 responses.

METHODS AND RESULTS

Sixty-four consecutive HFrEF patients who participated in a 3-month ECR program after CRT were investigated. Patients were categorized according to a median improvement in peak oxygen uptake (PV̇O2) after ECR of 7% as either good (n=32; mean percentage change in PV̇O2[%∆PV̇O2]=23.2%) or poor (n=32; mean %∆PV̇O2=2.5%) responders. There was no significant difference in baseline characteristics between the good and poor responders, except for PV̇O2(51% vs. 59%, respectively; P=0.01). The proportion of good CRT responders was similar between the good and poor responders (%∆LVEF ≥10%; 53% vs. 47%, respectively; P=NS). Overall, there was no significant correlation between %∆LVEF after CRT and %∆PV̇O2after ECR. Notably, among poor CRT responders (n=32), the prevalence of atrial fibrillation (0% vs. 29%; P<0.03) and baseline PV̇O2(48% vs. 57%; P<0.05) were significantly lower among those with a good (n=15) than poor (n=17) response to ECR.

CONCLUSIONS

In patients with HFrEF, good ECR and CRT responses are unrelated. A good PV̇O2response to ECR can be achieved even in poor CRT responders, particularly in those with a sinus rhythm or low baseline PV̇O2.

Clinical effectiveness of a dedicated cardiac resynchronization therapy pre-assessment clinic incorporating cardiac magnetic resonance imaging and cardiopulmonary exercise testing on patient selection and outcomes

BACKGROUND

Pre-procedural assessment of patients undergoing cardiac resynchronization therapy (CRT) is heterogenous and patients implanted with unfavorable characteristics may account for non-response. A dedicated CRT pre-assessment clinic (CRT PAC) was developed to standardize the review process and undertake structured pre-procedural evaluation. The aim of this analysis was to determine the effectiveness on patient selection and outcomes.

METHODS

A prospective database of consecutive patients attending the CRT PAC between 2013 and 2018 was analyzed. Pre-operative assessment included cardiac magnetic resonance (CMR) and cardiopulmonary exercise testing (CPET). Patients were considered CRT responders based on improvement in clinical composite score (CCS) and/or reduction in left ventricular end-systolic volume (LVESV) ≥ 15% at 6-months follow-up.

RESULTS

Of 252 patients reviewed in the CRT PAC during the analysis period, 192 fulfilled consensus guidelines for implantation. Of the patients receiving CRT, 82% showed improvement in their CCS and 57% had a reduction in LVESV ≥ 15%. The presence of subendocardial scar on CMR and a peak VO2 ≤ 12 ml/kg/min on CPET predicted CRT non-response. Two patients were unsuitable for CRT as they had end-stage heart failure and died during follow-up. The majority of patients initially deemed unsuitable for CRT did not suffer from unexpected hospitalization for decompensated heart failure or died from cardiovascular disease; only 8 patients (13%) received CRT devices during follow-up because of symptomatic left ventricular systolic impairment.

CONCLUSION

A dedicated CRT PAC is able to appropriately select patients for CRT. Pre-procedural investigation/imaging can identify patients unlikely to respond to, or may not yet be suitable for CRT.

Reverse remodelling by sacubitril/valsartan predicts the prognosis in heart failure with reduced ejection fraction

Aims

Despite well‐established benefits of sacubitril/valsartan for cardiac reverse remodelling and the prognosis of patients with heart failure with reduced ejection fraction (HFrEF), there are some patients with limited therapeutic response, even with optimal therapy. We assessed the treatment response to sacubitril/valsartan in patients with HFrEF, focusing on the association between reverse remodelling and the prognosis.

Methods and results

Using a retrospective cohort of consecutive patients with HFrEF treated with sacubitril/valsartan, we compared the time trajectory of cardiac function in 415 patients (1258 echocardiograms), according to the occurrence of cardiovascular death and hospitalization for HF during a median follow‐up of 19.1 (interquartile range, 10.9–27.6) months. A higher sacubitril/valsartan dose was associated with a better prognosis, whereas advanced age, diabetes, left ventricular (LV) hypertrophy, left atrial enlargement, and pulmonary hypertension were associated with a worse prognosis. Patients without an event (n = 337; 81.2%) showed LV reverse remodelling (LV ejection fraction ≥45% or LV end‐systolic volume reduction by 15% from baseline), which was typically observed within 6 months of sacubitril/valsartan treatment. Reverse remodelling achievement was significantly associated with a better prognosis. However, patients without reverse remodelling had a worse prognosis, as poor as that in patients with HFrEF not treated with sacubitril/valsartan.

Conclusions

In patients with HFrEF treated with sacubitril/valsartan, LV reverse remodelling reflects the treatment response and predicts the prognosis, whereas a lack of reverse remodelling indicates the lack of treatment benefits. Prediction and assessment of reverse remodelling may facilitate the selection of patients with greater benefits by sacubitril/valsartan.

Effect of Exercise Training in Heart Failure Patients Without Echocardiographic Response to Cardiac Resynchronization Therapy

Background: Cardiac resynchronization therapy (CRT) is an effective treatment of heart failure (HF) with ventricular dyssynchrony, but not all patients respond to a similar extent. We investigated the efficacy and safety of exercise training (ET) in patients without response to CRT.

Methods and Results: Thirty-four patients who participated in a 3-month ET program and underwent cardiopulmonary exercise testing at baseline and after the program were divided into 17 responders and 17 non-responders based on echocardiographic response criteria: either an increase in ejection fraction (EF) ≥10% or a reduction in left ventricular (LV) end-systolic volume ≥10%. Baseline characteristics including peak oxygen uptake (V̇O₂) and isometric knee extensor muscle strength (IKEMS) were similar in both groups, but non-responders had lower EF and larger LV. During the ET program, neither group had exercise-related adverse event including life-threatening ventricular arrhythmia. Peak V̇O₂ and IKEMS were significantly improved in both groups and there was no significant difference in change in peak V̇O₂ or IKEMS between responders and non-responders. On multiple regression analysis, change in IKEMS was an independent predictor of change in peak V̇O₂, whereas the response to CRT was not.

Conclusions: In HF patients undergoing CRT implantation, ET safely improved exercise capacity regardless of response to CRT, suggesting that even advanced HF patients without response to CRT can possibly benefit from ET.

Reverse remodelling and myocardial recovery in heart failure

Advances in medical and device therapies have demonstrated the capacity of the heart to reverse the failing phenotype. The development of normative changes to ventricular size and function led to the concept of reverse remodelling. Among heart failure therapies, durable mechanical circulatory support is most consistently associated with the largest degree of reverse remodelling. Accordingly, research to analyse human tissue after a period of mechanical circulatory support continues to yield a wealth of information. In this Review, we summarize the latest findings on reverse remodelling and myocardial recovery. Accumulating evidence shows that the molecular changes associated with heart failure, in particular in the transcriptome, metabalome, and extracellular matrix, persist in the reverse-remodelled myocardium despite apparent normalization of macrolevel properties. Therefore, reverse remodelling should be distinguished from true myocardial recovery, in which a failing heart regains both normal function and molecular makeup. These findings have implications for future research to develop therapies to repair fully the failing myocardium. Meanwhile, recognition by society guidelines of this new clinical phenotype, which is coming to be known as a state of heart failure remission, underscores the need to accurately define and identify reverse modelled myocardium for the establishment of appropriate therapies.