Non-invasive hemodynamic determination of patient-specific optimal pacing mode in cardiac resynchronization therapy

PURPOSE

Cardiac resynchronization therapy (CRT) devices have multiple programmable pacing parameters. The purpose of this study was to determine the best pacing mode, i.e., associated with the greatest acute hemodynamic response, in each patient.

METHODS

Patients in sinus rhythm and intact atrioventricular conduction were included within 3 months of implantation of devices featuring SyncAV and multipoint pacing (MPP) algorithms. The effect of nominal biventricular pacing using the latest activated electrode (BiV-Late), optimized atrioventricular delay (AVD), nominal and optimized SyncAV, and anatomical MPP was determined by non-invasive measurement of systolic blood pressure (SBP). CRT response was defined as SBP increase > 10% relative to baseline.

RESULTS

Thirty patients with left bundle branch block (LBBB) were included. BiV-Late increased SBP compared to intrinsic rhythm (128 ± 21 mmHg vs. 121 ± 22 mmHg, p = 0.0002). The best pacing mode further increased SBP to 140 ± 19 mmHg (p < 0.0001 vs. BiV-Late). The proportion of CRT responders increased from 40% with BiV-Late to 80% with the best pacing mode (p = 0.0005). Compared to BiV-Late, optimized AVD and optimized SyncAV increased SBP (to 134 ± 21 mmHg, p = 0.004, and 133 ± 20 mmHg, p = 0.0003, respectively), but nominal SyncAV and MPP did not. The best pacing mode was variable between patients and was different from nominal BiV-Late in 28 (93%) patients. Optimized AVD was the most frequent best mode, in 14 (47%) patients.

CONCLUSION

In patients with LBBB, the best pacing mode was patient-specific and doubled the magnitude of acute hemodynamic response and the proportion of acute CRT responders compared to nominal BiV-Late pacing.

TRIAL REGISTRATION

ClinicalTrials.gov : NCT03779802.

The effect of cardiac resynchronization therapy on arterial stiffness and central hemodynamic parameters

INTRODUCTION

Cardiac resynchronization therapy (CRT) is a device-based method of treatment which decreases morbidity and mortality in heart failure with reduced ejection fraction (HFrEF). This study was aimed to investigate the effects of CRT on hemodynamic and arterial stiffness parameters evaluated by noninvasive method, and determine whether there is a correlation between the changes after CRT in these parameters and the clinical response to CRT or not.

METHODS

The study included 46 patients with HFrEF who were planned to undergo CRT implantation. Before the CRT implantation, clinical and demographic data were recorded from all patients. Hemodynamic and arterial stiffness parameters were measured oscillometrically by an arteriograph before CRT implantation. The patients were re-evaluated minimum three months after CRT; the above-mentioned parameters were measured again and compared to the pre-CRT period.

RESULTS

Compared to the period before CRT, mean systolic blood pressure (SBP) (116.8 ± 19.1 mm Hg vs 127.7 ± 20.9 mm Hg, P = .005), central SBP (cSBP) (106.2 ± 17.3 mm Hg vs 116.8 ± 18.7 mm Hg, P = .015), cardiac output (CO) (4.6 ± 0.8 lt/min vs 5.1 ± 0.8 lt/min, P = .002), stroke volume (65.6 ± 16.3 mL vs 72.0 ± 14.9 mL), and pulse wave velocity (PWV) (10 ± 1.6 m/sec vs 10.4 ± 1.8 m/sec, P = .004) increased significantly in post-CRT period. In addition, the same parameters were significantly increased post-CRT period in patients with clinical response. However, there was not any similar increase in nonresponder patients.

CONCLUSION

This study demonstrated that SBP, CO, and PWV increased significantly after CRT. The modest increases in these parameters were observed to be associated with positive clinical outcomes.

Prognostic Usefulness of Systolic Blood Pressure One-Year Following Cardiac Resynchronization Therapy (from MADIT-CRT)

Low systolic blood pressure (SBP) is associated with increased mortality and heart failure in patients with left ventricular dysfunction. Data on the relation between SBP measured following cardiac resynchronization therapy implantation and subsequent clinical events are limited. We hypothesized that assessment of systolic blood pressure at 12 months after cardiac resynchronization therapy can be used to identify patients with increased risk for adverse cardiovascular outcomes. The study population comprised 1000 patients who underwent cardiac resynchronization therapy implantation in MADIT-CRT. Outcomes were compared between patients with low (<110 mm Hg) and preserved SBP (≥110 mm Hg) at 1 year. At 1 year following cardiac resynchronization therapy, 800 patients (80%) had preserved systolic blood pressure. Kaplan-Meier survival analysis showed that the rate of heart failure or death during subsequent follow-up was significantly higher among patients with low SBP as compared with a preserved SBP at 12 months (2-year rates: 20% vs 12%, respectively; log-rank p value = 0.009 for the overall difference during follow-up). Consistently, multivariate analysis showed that patients with preserved SBP at 1 year had a 29% lower risk of HF or death when compared with the low SBP group (p = 0.024). The association between SBP measured following cardiac resynchronization therapy implantation and subsequent clinical events was more pronounced among patients with nonischemic cardiomyopathy (p value for SBP-by-HF etiology interaction = 0.034). In conclusion, assessment of SBP following cardiac resynchronization therapy can be used for improved long-term risk stratification in this population.

Cardiac resynchronization therapy and arterial blood pressure: a bonus for hemodynamic improvement

The association between low blood pressure and prognosis in patients with heart failure has been controversial, with some reports suggesting an increased mortality for patients with the lowest blood pressures. Cardiac resynchronization therapy has become an established major therapeutic option for patients with heart failure and left ventricular dyssynchrony. It has been shown to improve functional capacity, left ventricular systolic function and survival in patients with heart failure. However, it is not known if this improvement in systolic function translates into an increase in arterial blood pressure. Here we discuss a recent publication evaluating the effect of cardiac resynchronization therapy on systolic blood pressure, diastolic blood pressure and pulse pressure. This study shows that cardiac resynchronization therapy is associated with a modest increase in systolic blood pressure and pulse pressure in patients with heart failure. These findings will be summarized and discussed with readily available clinical data.

Trials on the effect of cardiac resynchronization on arterial blood pressure in patients with heart failure

Cardiac resynchronization therapy (CRT) increases cardiac performance in patients with heart failure, but its effect on arterial pressure is not well established. To determine the effect of CRT on systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) a systematic review using standard nomenclatures for CRT was done in Scopus (MEDLINE and Embase), Cochrane Controlled Trials Register, National Institutes of Health http://www.ClinicalTrials.gov database, and bibliography of select meta-analyses for studies evaluating CRT in patients with dilated cardiomyopathy. Two independent investigators extracted the articles based on predefined criteria. The primary outcome was difference in arterial pressure parameters from baseline to after CRT in nonrandomized cohort trials. This was then validated by comparing the change in arterial pressure between CRT and medical therapy groups in randomized controlled trials. A random-effects model was used for analyses. Analyses of 15 nonrandomized studies showed that CRT resulted in an increase (from baseline) in SBP by 4.4 mm Hg (95% confidence interval [CI] 0.8 to 8.0, p = 0.02), no change in DBP (p = 0.21), and an increase in PP by 2.8 mm Hg (95% CI 1.0 to 4.6, p = 0.003). Results from the 3 randomized controlled trials were concordant with an increase in SBP by 3.9 mm Hg (95% CI 1.1 to 6.8, p = 0.007), no effect on DBP (p = 0.40), and an increase in PP by 4.3 mm Hg (95% CI 4.1 to 4.5, p <0.001) compared to medical therapy. In conclusion, CRT is associated with a modest increase in SBP and PP in patients with heart failure.

[Optimal electrode placement. What to consider during implantation of a biventricular pacemaker?]

Since the introduction of transvenous left ventricular lead systems nearly a decade ago, resynchronization therapy has gained widespread acceptance and has become a growing field in heart failure therapy. Due to the increasing numbers of implanting centers and physicians, the need for adequate education is increasing. This article describes and illustrates the anatomical background, the technical opportunities and pitfalls, which have to be overcome, to achieve an implanting success rate of 95% to 98%, as can be achieved by well-trained physicians under optimal conditions.