Changes in parameters of right ventricular function with cardiac resynchronization therapy

The Effect of Cardiac Resynchronization Therapy on Right Ventricular Function: A Systematic Review and Meta-Analysis

Background: Right ventricular (RV) failure is an important predicting factor regarding overall and event-free survival regardless of baseline left ventricular (LV) function in patients with severe heart failure (HF). Previous studies have indicated that cardiac resynchronization therapy (CRT) improves LV and RV reverse remodeling in patients with systolic dyssynchrony within the left ventricle. However, there is conflicting evidence regarding the role of CRT in RV function. The aim of this systematic review and meta-analysis was to examine the implications of CRT on RV function indices. Methods: A systematic literature search was conducted using the MedLine and EMBASE databases and the Cochrane Library from their inception until 18 March 2024. Eligible were studies providing information on RV function indices, both at baseline and after CRT. Evidence was summarized using random-effects meta-analytic models. Results: In total, 30 studies were deemed eligible. CRT resulted in a significant improvement in right ventricular fractional area change (mean difference (MD) 5.11%, 95% confidence interval (CI) 2.83 to 7.39), tricuspid annular plane systolic excursion (TAPSE, MD 1.63 mm, 95% CI 1.10 to 2.16), and myocardial systolic excursion velocity (MD 1.85 cm/s, 95% CI 1.24 to 2.47) as well as a significant decrease in pulmonary artery systolic pressure (MD -6.24 mmHg, 95% CI -8.32 to -4.16). A non-significant effect was observed on TAPSE to PASP ratio and right ventricular global longitudinal strain. Conclusions: Our meta-analysis demonstrates that CRT is associated with a significant improvement in echocardiographic parameters of RV function. Further investigation is necessary to elucidate how these changes, both independently and in conjunction with LV improvement, impact patients' long-term prognosis, and to identify the specific patient populations expected to derive the greatest benefit.

Right Ventricular Response to Cardiac Resynchronization Therapy: A Three-Dimensional and Speckle Tracking Echocardiographic Study

Cardiac resynchronization therapy (CRT) induces left ventricle reverse remodeling; however, its effects on right ventricular (RV) volumes and function were not well described. This study aimed to assess the effects of CRT on RV. Of 112 patients, 63 enrolled with a mean age of 62.77 ± 7.23 years, including 40 males (63.5%). All patients met criteria for CRT implantation and were followed at 3-month and 6-month intervals. Standard 2-dimensional/3-dimensional (3D) echocardiography and speckle-tracking analyses were conducted for assessment of LV and left atrium (LA). RV maximum diameters, tricuspid lateral annular systolic velocity, tricuspid annular plane systolic excursion, fractional area change, RV global (RV 4-chamber strain (RV4CSL), and RV free wall strain (RVFWSL), in addition to 3D echocardiographic assessment of RV, were done before CRT implantation and at follow-up visits. Mean follow-up period was 6.76 ± 1.25 months. A total of 48 patients (76.2%) were LV responders (LVR) whereas the rest were nonresponders (LVNR). Both groups had similar baseline characteristics, risk factors, device implantation, and programming values. Only LVR had significant reduction in RV basal diameter, together with significant improvement of RV systolic performance: systolic velocity, fractional area change, RV4CSL, RVFWSL, and 3D-derived RV volumes and ejection fraction, compared with baseline values. In addition, pulmonary arterial systolic pressure decreased in LVR with reduction of tricuspid regurgitation severity. LV response, percentage change of RV4CSL, LA end-systolic volume index, and LA emptying fraction at 3-month follow-up were the most independent predictors of RV response by multivariate analysis. Reduced left ventricular end-systolic volume >13.5% had 92.3% sensitivity and 81.8% specificity. In conclusion, CRT-induced RV reverse remodeling and improved RV-arterial coupling. These effects were associated with left side response to CRT.

Improved Right Ventricular Systolic Function After Cardiac Resynchronization Therapy in Patients With Heart Failure

BACKGROUND

Since the introduction of cardiac resynchronization therapy (CRT) to improve left ventricular function, the effect of CRT on the right ventricle in patients with heart failure has not been well described.

METHODS

We evaluated the effect of CRT on right ventricular systolic function in 20 patients (80% men; mean [SD] age, 58.5 [9.8] y) with cardiomyopathy and right ventricular systolic dysfunction (New York Heart Association class III or IV, left ventricular ejection fraction ≤35%, and QRS interval ≥120 ms). The median follow-up time was 15 months. Right ventricular systolic function, defined as a tricuspid annular plane systolic excursion (TAPSE) index of 16 mm or less, was evaluated in patients before and after CRT.

RESULTS

Twelve (60%) patients had ischemic cardiomyopathy, and 12 (60%) patients had left bundle branch block detected using surface electrocardiogram. The mean (SD) QRS duration was 160.5 (24.4) ms. From before CRT to the time of follow-up after CRT, the mean (SD) ejection fraction increased significantly from 22.5% (5.6%) to 29.4% (7.4%) (P < .001). The mean (SD) TAPSE index also increased significantly from 13.70 (1.78) mm to 16.50 (4.77) mm (P = .018). Eleven (55%) patients showed improved right ventricular systolic function (TAPSE ≥16 mm) after CRT. Patients with a favorable right ventricular response to CRT were significantly older (64.6 [8.2] y vs 53.6 [8.4] y, respectively) and more likely to have nonischemic origin of cardiomyopathy than were patients with unimproved right ventricular function (66.7% vs 18.2%, respectively).

CONCLUSION

Our findings indicate that CRT is associated with improved right ventricular systolic function in patients with heart failure and right ventricular systolic dysfunction. Patients with nonischemic heart disease more often show improved right ventricular function after CRT.

Echocardiographic Assessment of Right Ventriculo-arterial Coupling: Clinical Correlates and Prognostic Impact in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

BACKGROUND

Right ventriculo-arterial coupling (RV-PA) can be estimated by echocardiography using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) and it has prognostic value in the general heart failure (HF) population. We aimed to study the clinical correlates and prognostic value of RV-PA in HF patients undergoing cardiac resynchronization therapy (CRT).

METHODS

We retrospectively studied 70 HF patients undergoing CRT implantation.

RESULTS

RV-PA coupling was estimated by TAPSE/PASP ratio using baseline echocardiography. Non-response to CRT was defined as improvement of left ventricular ejection fraction < 5% in a follow-up echo 6-12 months after CRT. Those with lower TAPSE/PASP ratios (worse RV-PA coupling) had higher NT-proBNP concentrations and increased E/e' ratio. TAPSE/PASP ratio and PASP, but not TAPSE, predicted nonresponse to CRT with TAPSE/PASP ratio showing the best discriminative ability with a sensitivity of 76% and specificity of 71%. Among these parameters, PASP independently predicted all-cause mortality.

CONCLUSIONS

RV-PA coupling estimated by TAPSE/PASP ratio was associated with established prognostic markers in HF. It numerically outperformed PASP and TAPSE in predicting the response to CRT. Our data suggest that this simple and widely available echocardiographic parameter conveys significant pathophysiological and prognostic meaning in HF patients undergoing CRT.

Usefulness of Cardiac Resynchronization Therapy in Patients With Continuous Flow Left Ventricular Assist Devices

The benefit of cardiac resynchronization therapy in patients supported by a left ventricular assist device (LVAD) is unknown. There are currently no guidelines regarding the continuation, discontinuation or pacemaker (PM) settings post-LVAD implant. The aim of the study was to assess the hemodynamic benefit of biventricular (BiV) pacing in LVAD patients. We studied 22 patients supported by LVADs (age 62 ± 9, 21 males) who had received a BiV PM before LVAD implant. A total of 123 complete sets of hemodynamics were obtained during BiV pacing (n = 54), right ventricular (RV) pacing (n = 54), and intrinsic rhythm (n = 15). There were no significant differences in right atrial (RA) pressure, mean pulmonary artery pressure (mPA), PCWP, cardiac output, PA saturation (PASat) and right ventricular stroke work index between BiV and RV pacing. Hemodynamics obtained during intrinsic rhythm in 15 non-PM-dependent patients were not significantly different compared with those obtained during BiV or RV pacing. Furthermore, hemodynamics were similar at different heart rates ranging 50 to 110 beats/min. Right ventricular stroke work index was significantly lower at the highest heart rate compared with baseline and lowest heart rates suggesting decreased RV performance at higher heart rate. In conclusion, BiV pacing does not have any acute hemodynamic benefit compared with RV pacing or intrinsic rhythm in LVAD patients. A lower heart rate may confer better RV performance.

Right ventricular failure management

PURPOSE OF REVIEW

Review recent advances in the diagnosis and management of right ventricular (RV) failure.

RECENT FINDINGS

Temporary and durable device-based management of RV failure has emerging applications.

SUMMARY

Research advances and clinical management in RV failure have been limited by a lack of consensus on a universal definition. Echocardiographic and cardiac MRI-based predictors of RV failure are imperfect. Combinations of hemodynamic and imaging variables may have better predictive value. Loading conditions and ventriculo-arterial coupling play important roles in RV function. The current treatment approach to RV failure includes a combination of inotropy and vasodilatation but lacks conclusive evidence. Emerging biochemical and molecular targets hold promise but have yet to be proven in human studies.

Changes in parameters of right ventricular function with cardiac resynchronization therapy

BACKGROUND

Studies have shown that cardiac resynchronization therapy (CRT) significantly improves right ventricle (RV) size and function in patients with heart failure (HF).

HYPOTHESIS

CRT does not lead to improvement in RV function independent of baseline clinical variables.

METHODS

A systematic search of studies published between 1966 to August 31, 2015 was conducted using Pub Med, CINAHL, Cochrane CENTRAL and the Web of Science databases. Studies reporting tricuspid annular plane systolic excursion (TAPSE) or RV basal strain or RV long axis diameter or RV short axis diameter or RV fractional area change (FAC), before and after CRT, were identified. A meta-analysis was performed using random effects with inverse variance method to determine the pooled mean difference in various parameters of RV function after CRT. Meta-regression analysis was performed to test the relationship between change in various parameters of RV functions after CRT and covariates- age, QRS duration, and left ventricular ejection fraction (LVEF).

RESULTS

Thirteen studies (N=1541) were selected for final analysis. CRT therapy led to statistically significant increases in TAPSE [1.21 (95% CI 0.55-1.86; p<0.001)], RV FAC [2.26 (95% CI 0.50-4.01; p<0.001)] and basal strain [2.82 (95% CI 0.59-5.05; p<0.001)] and statistically significant decreases in mean RV long axis diameter [-2.94 (95% CI -5.07- -0.82; p=0.005)] and short axis diameter [-1.39 (95% CI -2.10- -0.67; p=0.876)] after a mean follow up period of 9 months. However, after meta-regression analysis for age, QRS duration, and baseline LVEF as covariates, there was no significant improvement in any of the parameters of RV function after CRT.

CONCLUSION

There was a statistically significant improvement in TAPSE, RV basal strain, RV fractional area, RV long axis and short axis with CRT. However, improvement in these echocardiographic parameters of RV function after CRT was not independent of baseline clinical variables but statistically dependent on age, QRS duration and baseline LVEF.