Functional capacity and gender-related differences in Fabry disease

Background

Fabry disease (FD) is a rare x-linked lysosomal storage disease characterized by accumulation of glicosphingolipids in several organs, including the heart. Cardiac involvement manifests as left ventricular (LV) hypertrophy, often complicated by myocardial fibrosis. The impact of disease on functional capacity is not well defined, as well as the potential gender-related differences.

Aim

To evaluate the functional capacity in a cohort of FD patients with different degree of cardiac involvement.

Methods

Seventy-two patients were prospectively enrolled from March 2015 to December 2019. Patients underwent cardiac magnetic resonance (CMR) and cardiopulmonary exercise test (CPET) with cycle ergometer. In addition to standard CPET parameters, Chronotropic Index (CI) was calculated as (HR max − HR rest) / (HR max predicted − HR rest), adjusting with HR max predicted calculated as 119 + (HR rest/2) − (age/2) in case of beta-blockers treatment.

Results

CMR showed left ventricle (LV) hypertrophy (LV mass greater than normal reference value) in 36.1% of patients, LGE and reduced T1 values were detected in 30.6% and 59.7% of subjects respectively. Twenty-eight patients were males (39%), the median age was 40 (28–54) [median (25th–75th)] years and only 11 (15%) subjects were on beta-blockers. All subjects performed a maximal test [RQ max = 1.21 (1.14–1.26)] using a ramp protocol of 15 (15–20) Watt. The absolute peakVO2 was 18.2 (15.75–24.08) mL/min/kg, whilst the percentage of predicted peakVO2 was 67.7 (57.3–76.6)%. The chronotropic response of the overall population was characterized by reduced peak heart rate (HRmax) [80.3 (73.8–87.6)% of predicted], and diminished chronotropic index (CI) [0.67 (0.55–0.77) normal value: 0.80], but preserved heart rate reserve (HRR) [21 (12–28) bpm]. Ventilatory efficiency was preserved [VE/VCO2 = 25.70 (23.18–28.00)]. At gender analysis, men showed higher absolute peakVO2 [men vs females: 19.95 (17.20–28.28) vs 17.80 (15.50–21.28) mL/min/kg, p=0.02] but lower percentage of predicted [64.24 (52.58–70.61) vs 70.75 (59.05–78.02)%, p<0.001] than females. No differences between genders were observed in chronotropic response [HRmax = 138 (108–154) vs 142 (135–153) bpm, p=0.38; HRR = 22 (13–36) vs 20 (11–26), p=0.097; CI: 0.67 (0.51–0.76) vs 0.67 (0.58–0.79), p=0.33], whilst females showed a lower peak O2 pulse (VO2/HR) than males [men vs females: 12.08 (10.04–13.64) vs 7.76 (6.88–9.22), p<0.001], possibly related to gender differences in LV dimensions and stroke volume.

Conclusions

This large cohort of FD patients with different degree of cardiac involvement showed a significantly impaired functional capacity, mainly characterized by relevant chronotropic incompetence (independent from the use of beta-blockers), consistent with systemic autonomic dysfunction. The degree of chronotropic incompetence was similar between the genders, but females showed higher predicted peakVO2 despite a lower peak O2 pulse.

Funding Acknowledgement

Type of funding sources: None.

Right ventricle morphological and functional phenotypes in heart failure with reduced ejection fraction: from pathophysiology to prognostic significance

Background

Right ventricle (RV) remodeling is a marker of advanced disease and impaired prognosis in heart failure reduced ejection fraction (HFrEF) patients [1]. The assessment of RV remodeling is limited with standard echocardiography. Three-dimensional speckle-tracking echocardiography (3DSTE), with advanced post-processing, allows for RV shape and regional function assessment, potentially providing additional information [2].

Purpose

1) to describe global and regional RV shape and function in a HFrEF cohort of patients; 2) to define RV remodeling phenotypes according with pulmonary haemodynamics; 3) to test the prognostic significance of RV shape and functional parameters.

Methods

81 HFrEF patients were prospectively enrolled and followed-up (median time 760 days) for the composite end-point of death, heart failure hospitalization, heart transplant and left ventricular assist device implantation. They received standard 3DSTE evaluation, consisting of end-diastolic volume index (EDVi), end-systolic (ES) volume index (ESVi) and ejection fraction (EF) measurement via commercial software (TomTec Imaging Systems GmbH, Germany). Advanced post-processing provided RV free-wall and septal mean curvatures (Km) and minimum principal strain (MPS) [3] quantification. A subgroup of 40 subjects underwent right heart catheterization (RHC) and were classified in: group A – no pulmonary hypertension (PH) (n=15), group B – PH but normal pulmonary vascular resistance (PVR) (n=15) and group C – PH and increased PVR (n=10). Roc curves were used to identify RV parameters able to discriminate subjects belonging to group A. Prognostic significance of RV remodeling parameters was tested for the composite end-point.

Results

Patients who did receive RHC showed lower ES free-wall Km (0.052 vs 0.058 mm-1, p<0.01) and impaired RV EF (35.9 vs 40.9%, p=0.04) if compared to those who didn't. A progressive RV dilatation, global and regional dysfunction were observed according with the degree of pulmonary haemodynamic worsening (ES free-wall Km 0.054, 0.052, 0.044 mm-1, p<0.02 and free-wall MPS −23.1, −21.3, −19.2%, p<0.02, for groups A, B and C, respectively, Fig. 1). RV ESVi, ES free-wall Km, global and regional MPS showed a good ability to discriminate patients without PH (ES free-wall MPS Sensitivity=0.72, 1-Specificity=0.4, area under curve=0.71). At univariable Cox Regression, the presence of more than moderate mitral regurgitation (MR), RV EF <38% and free-wall MPS >−22.4% (threshold discriminating normal pulmonary hemodynamic) resulted statistically associated with prognosis (Fig. 2).

Conclusion

In HFrEF patients, RV remodeling is progressively associated with unfavourable pulmonary haemodynamic, with a free-wall negative remodeling (abnormal curvature) resulting in loss of systolic function. RV free-wall function is tightly associated with the development of PH. 3DSTE indexes of RV global and regional function showed prognostic significance together with MR coexistence.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): IRCCS Policlinico San Donato is a clinical research hospital partially funded by the Italian Ministry of Health Figure 1. End-systolic MPS distributionFigure 2. Kaplan-Meier survival analysis

The value of 3D-speckle tracking longitudinal strain for the assessment of left ventricular function recovery in ischemic heart failure patients undergoing surgical remodeling:the RECOVERY-IN study

Background

Three-dimensional (3D) speckle-tracking echocardiography is largely employed to evaluate left ventricle (LV) morphology and function.

Purpose

To investigate LV function before and after surgical ventricular reconstruction (SVR) through the analysis of global (GLS) and segmental (SLS) longitudinal strain, and the derived mechanical dispersion (MD).

Methods

Twenty patients eligible for SVR, with previous LV remodelling and ischemic heart failure (HF), received 3D echocardiographic evaluation before SVR and at 6-months follow-up; 15 normal controls, matched by age and BSA, were enrolled. Standard off-line GLS analysis was performed with 4D LV-ANALYSIS©; advanced segmental analysis was accomplished automatically through in-house numerical post-processing.

Results

Before SVR, GLS deteriorated compared to normal subjects (−6.7% vs. −19.6%, P<0.0001) as confirmed by SLS at each LV segment basal, mid and apical level (P<0.0001); MD was higher than in controls (P<0.001) and markedly increased from basal to apical LV segment. After SVR, GLS significantly improved from −6.7% to −11.3% (P<0.0001). Analysis of variance showed that SLS recovery was higher in the basal region (7.25%) than in both mid (4.06%, P=0.001) and apical (1.92%, P<0.0001) segments, respectively, with adjustment for baseline values.

Conclusions

After SVR, LV longitudinal strain mostly improves in the basal segments, outlining the role of the remote myocardium in enhancing LV function through an extensive volume reduction; post-surgical MD reduction indicates a more homogeneous myocardial contraction.

Heath map of longitudinal strain (%)

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): IRCCS Policlinico San Donato is a clinical research hospital partially funded by the Italian Ministry of Health.