Chen-Huan Chen

BACKGROUND: Ventricular pacing can improve hemodynamics in heart failure patients, but direct effects on left ventricular (LV) function from varying pacing site and atrioventricular (AV) delay remain unknown. We hypothesized that the magnitude and location of basal intraventricular conduction delay critically influences pacing responses and that single-site pacing in the delay-activated region yields similar or better responses to biventricular pacing. METHODS AND RESULTS: Aortic and LV pressures were measured in 18 heart failure patients (mean+/-SD: LV ejection fraction, 19+/-7%; LV end-diastolic pressure, 25+/-8 mm Hg; QRS duration, 157+/-36 ms). Data under normal sinus rhythm were compared with ventricular pacing (VDD) at varying sites and AV delays (randomized order). Right ventricular (RV) apical or midseptal pacing had negligible contractile/systolic effects. However, LV free-wall pacing raised dP/dtmax by 23.7+/-19.0% and pulse-pressure by 18.0+/-18.4% (P<0.01). Biventricular pacing yielded less change (+12.8+/-9.3% in dP/dtmax, P<0.05 versus LV). Pressure-volume analysis performed in 11 patients consistently revealed minimal changes with RV pacing but increased stroke work and lower end-systolic volumes with LV pacing. Optimal AV intervals averaged 125+/-49 ms, and within this range, AV delay had less influence on LV function than pacing site. Basal QRS duration positively correlated with %DeltadP/dtmax (P<0.005), but pacing efficacy was not associated with QRS narrowing. Conduction delay pattern generally predicted pacing sites with most effect. CONCLUSIONS: VDD pacing acutely enhances contractile function in heart failure patients with intraventricular conduction delay. Single-site pacing at the site of greatest delay achieves similar or greater benefits to biventricular pacing in such patients. These data clarify pacing-effect mechanisms and should help in candidate identification for future studies.

Background: While disease-modifying therapies exist for heart failure (HF) with reduced left ventricular ejection fraction (LVEF), few options are available for patients in the higher range of LVEF (&gt;40%). Sacubitril/valsartan has been compared with a renin-angiotensin-aldosterone–system inhibitor alone in 2 similarly designed clinical trials of patients with reduced and preserved LVEF, permitting examination of its effects across the full spectrum of LVEF. Methods: We combined data from PARADIGM-HF (LVEF eligibility≤40%; n=8399) and PARAGON-HF (LVEF eligibility≥45%; n=4796) in a prespecified pooled analysis. We divided randomized patients into LVEF categories: ≤22.5% (n=1269), &gt;22.5% to 32.5% (n=3987), &gt;32.5% to 42.5% (n=3143), &gt; 42.5% to 52.5% (n=1427), &gt; 52.5% to 62.5% (n=2166), and &gt;62.5% (n=1202). We assessed time to first cardiovascular death and HF hospitalization, its components, and total heart failure hospitlizations, all-cause mortality, and noncardiovascular mortality. Incidence rates and treatment effects were examined across categories of LVEF. Results: Among 13 195 randomized patients, we observed lower rates of cardiovascular death and HF hospitalization, but similar rates of noncardiovascular death, among patients in the highest versus the lowest groups. Overall sacubitril/valsartan was superior to renin-angiotensin-aldosterone–system inhibition for first cardiovascular death or heart failure hospitalization (Hazard Ratio [HR] 0.84 [95% CI, 0.78–0.90]), cardiovascular death (HR 0.84 [95% CI, 0.76–0.92]), heart failure hospitalization (HR 0.84 [95% CI, 0.77–0.91]), and all-cause mortality (HR 0.88 [95% CI, 0.81–0.96]). The effect of sacubitril/valsartan was modified by LVEF (treatment-by-continuous LVEF interaction P =0.02), and benefit appeared to be present for individuals with EF primarily below the normal range, although the treatment benefit for cardiovascular death diminished at a lower ejection fraction. We observed effect modification by LVEF on the efficacy of sacubitril/valsartan in both men and women with respect to composite total HF hospitalizations and cardiovascular death, although women derived benefit to higher ejection fractions. Conclusions: The therapeutic effects of sacubitril/valsartan, compared with a renin-angiotensin-aldosterone–system inhibitor alone, vary by LVEF with treatment benefits, particularly for heart failure hospitalization, that appear to extend to patients with heart failure and mildly reduced ejection fraction. These therapeutic benefits appeared to extend to a higher LVEF range in women compared with men. Clinical Trial Registration: https://www.clinicaltrials.gov . Unique identifiers: NCT01920711 (PARAGON-HF), NCT01035255 (PARADIGM-HF).

OBJECTIVE: To examine the relationship between brachial and central carotid pressures and target organ indices at baseline and their association with future mortality. METHODS: We examined, cross-sectionally and longitudinally, the relations of baseline systolic and pulse pressures in central (calibrated tonometric carotid pulse) and peripheral (brachial, mercury sphygmomanometer) arteries to baseline left ventricular mass, carotid intima-media thickness, estimated glomerular filtration rate, and 10-year all-cause and cardiovascular mortality in 1272 participants (47% women aged 30-79 years) from a community of homogeneous Chinese. RESULTS: Left ventricular mass was more strongly related to central and peripheral systolic pressures than pulse pressures. Intima-media thickness and glomerular filtration rate were more strongly related to central pressures than peripheral pressures. A total of 130 participants died, 37 from cardiovascular causes. In univariate analysis, all four blood pressure variables significantly predicted all-cause and cardiovascular mortality. Each blood pressure variable was entered into the multivariate models, both individually and jointly with another blood pressure variable. After adjustment for age, sex, heart rate, BMI, current smoking, glucose, ratio of total cholesterol to high-density lipoprotein cholesterol, carotid-femoral pulse wave velocity, left ventricular mass, intima-media thickness, and glomerular filtration rate, only central systolic pressure consistently and independently predicted cardiovascular mortality (hazards ratio, 1.30 per 10 mmHg). No significant sex interactions were observed in all analyses. CONCLUSION: Systolic and pulse pressures relate differently to different target organs. Central systolic pressure is more valuable than other blood pressure variables in predicting cardiovascular mortality.