Changes in heart rate variability among cardiac resynchronization therapy patients

Rafael Correo, de izquierdas, y Alvaro Noboa, magnate conservador, vencieron con un discurso clientelista en el pais mas inestable de America Latina.

VT begets VT—and other bad stuff—in patients treated with CRT-D

Complications and Mortality Following CRT-D Versus ICD Implants in Older Medicare Beneficiaries With Heart Failure

There are conflicting data regarding the efficacy of cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and without left bundle branch block. We evaluated the long-term clinical outcomes of 537 non-left bundle branch block patients with mild HF enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study by QRS duration or morphology further stratified by PR interval. At 7 years of follow-up, the cumulative probability of HF hospitalization or death was 45% versus 56% among patients randomized to implantable cardioverter-defibrillator and CRT with defibrillator (CRT-D), respectively (P=0.209). Multivariable-adjusted subgroup analysis by QRS duration showed that patients from the lower quartile QRS duration group (≤ 134 ms) experienced 2.4-fold (P=0.015) increased risk for HF hospitalization or death with CRT-D versus implantable cardioverter-defibrillator only therapy, whereas the effect of CRT-D in patients from the upper quartiles group (QRS>134 ms) was neutral (hazard ratio [HR] =0.97, P=0.86; P value for interaction =0.024). In a second analysis incorporating PR interval, patients with prolonged QRS (>134 ms) and prolonged PR (>230 ms) were protected with CRT-D (HR=0.31, P=0.003), whereas the association was neutral with prolonged QRS (>134 ms) and shorter PR (≤ 230 ms;, HR=1.19, P=0.386; P value for interaction =0.002). The effect was neutral, regardless of morphology, right bundle branch block (HR=1.01, P=0.975), and intraventricular conduction delay (HR=1.31, P=0.172). Overall, patients with mild HF but without left bundle branch block morphology did not derive clinical benefit with CRT-D during long-term follow-up. Relatively shorter QRS was associated with a significantly increased risk with CRT-D relative to implantable cardioverter-defibrillator -only. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00180271, NCT01294449, and NCT02060110.

Effect of Cardiac Resynchronization Therapy in Patients With Insulin-Treated Diabetes Mellitus

There are limited data regarding racial differences in response to cardiac resynchronization therapy with defibrillator (CRT-D). We assessed the effectiveness of CRT-D, as compared to implantable cardioverter defibrillator (ICD) therapy alone, in reducing the risk of heart failure (HF) or death and changes in cardiac volumes among 1638 (90%) white patients and 143 (8%) black patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT). Enrolled black patients displayed a higher frequency of diabetes mellitus, treated hypertension, higher creatinine levels, and a lower distance walked in the baseline 6-minute walk test. Kaplan-Meier survival analysis showed that at 3 years of follow-up the cumulative probability of HF or death was higher among blacks (29%) as compared with whites (22%; P = 0.05). Both black and white patients experienced similar and pronounced reductions in cardiac volumes with CRT-D therapy (all P values for comparison between the two groups >0.10). Risk reduction conferred by CRT-D therapy as not significantly different between blacks and whites (hazard ratio = 0.78 and 0.60, respectively; P for the difference = 0.44). However, possibly due to sample size limitations the CRT-D versus ICD only adjusted risk for HF/death in blacks was not statistically significant. Black patients in MADIT-CRT experienced increased risk of HF or death as compared with whites, but displayed a similar magnitude echocardiographic response to CRT-D. These findings suggest that cardiac resynchronization therapy may be an effective therapeutic modality in black patients. However, further studies are needed to assess the clinical response to CRT-D in this high-risk population.

Effect of Cardiac Resynchronization Therapy-Defibrillator Implantation on Health Status in Patients With Mild Versus Moderate Symptoms of Heart Failure

Clinical usefulness of gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography with phase analysis for the management of patients with isolated ventricular noncompaction

Background Over a quarter of all cardiac resynchronization therapy (CRT) implants are upgrades from previous devices, mainly from implantable cardioverter-defibrillator (ICD). In comparison to CRT with defibrillator (CRT-D) de novo implantation, upgrade from ICD to CRT-D carries higher risk of complications. Limited number of studies evaluated predictors of death in patients undergoing upgrade from ICD to CRT-D. Aim To determine mortality predictors and outcome in patients undergoing upgrade from ICD to CRT-D in comparison to subjects with CRT-D de novo implantation. Methods Study population consisted of 595 consecutive patients with CRT-D implanted between 2002 and 2015 in tertiary care university hospital, in a densely inhabited, urban region of Poland (480 subjects [84.3%] with CRT-D de novo implantation; 115 patients [15.7%] upgraded from ICD to CRT-D). Results The median follow-up was 1692 days (range: 457–3067). All-cause mortality in patients upgraded from ICD was significantly higher than in subjects with CRT-D implanted de novo (43.5% vs. 35.5%, P=0.045). On multivariable regression analysis, left ventricular end-systolic diameter (HR 1.07, 95% CI 1.02–1.11, P=0.002), creatinine level at baseline (HR 1.01, 95% CI 1.00–1.02, P=0.01), NYHA IV class at baseline (HR 2.36, 95% CI 1.00–5.53, P=0.049) and cardiac device-related infective endocarditis (CDRIE) during follow up (HR 2.42, 95% CI 1.02–5.75, P=0.046) were identified as independent predictors of higher mortality in patients with CRT-D upgraded from ICD. Conclusions Mortality rate in patients upgraded from ICD is higher in comparison to CRT-D de novo implanted subjects, and reaches almost 45% within 4.5 years. Left ventricular dimensions, creatinine level, high NYHA class at baseline and infective endocarditis during follow up are independent mortality predictors in patients with CRT-D upgraded from ICD.

Introduction: Prolonged PR intervals may impair atrioventricular mechanical coupling and adversely affect cardiac performance. We hypothesize that patients with advanced systolic heart failure, wide QRS complexes, and prolonged PR intervals will have improved survival from cardiac resynchronization therapy with defibrillator (CRT-D) regardless of whether left bundle branch block (LBBB) or non-LBBB is present. Methods: Patients enrolled in the optimal pharmacologic therapy (OPT) and CRT-D arms of the COMPANION trial were included in a multivariable Cox model of all-cause mortality as a function of presence of LBBB and value of PR interval at baseline. Hazard ratios representing the mortality reduction for CRT-D versus OPT were estimated together with pointwise 95% confidence intervals (CIs). Results: A total of 308 OPT and 595 CRT-D patients were included in the analysis. In both the LBBB (n=648) and non-LBBB (n=255) subgroups, the mortality reduction associated with CRT-D compared to OPT was greater with increasingly prolonged baseline PR interval (Figure 1, p=0.02 for each subgroup). Hazard ratios for CRT-D versus OPT (with 95% CIs) for PR intervals of 200ms and 250ms were 0.51 [0.35,0.74] and 0.30 [0.18,0.50] respectively for the LBBB subgroup, and 0.86 [0.50,1.5] and 0.39 [0.18,0.86] respectively for the non-LBBB subgroup. For non-LBBB patients with PR interval ≤200ms, there was no evidence of mortality benefit with CRT-D (p=0.60). Conclusions: In patients with advanced systolic heart failure, wide QRS complexes, and prolonged PR intervals, restoration of atrioventricular mechanical coupling with CRT-D may improve survival in both LBBB and non-LBBB recipients. In patients with non-LBBB, a benefit from CRT-D may occur in patients with prolonged PR intervals. Figure 1: Risk for all-cause mortality by hazard ratios stratified according to PR interval quartiles.

Studies have assessed changesin autonomic variables in terms of heart rate variability (HRV) during meditation, but their results have been conflicting. Recently, Telles and colleagues’ excellent study 1 compared changes in HRV measures during the first four meditative states—cancalata (random thinking), ekagrata (nonmeditative focusing), dharana (meditative focusing), and dhyana (effortless meditation)— described in traditional yoga texts. Their results revealed that the discrepancy in changes in HRV measures might be due to the different stages. At the end of the Discussion section, the authors mention the ultimate state in yoga, samadhi, which manifests with breath suspension. They did not explore this advancedmeditativestateintheirstudy.Therefore,wewould like to share our results about changes in HRV measures during breath suspension. We collected and compared HRV measures in time and frequency domains, along with heart rate and blood pressure, during random thinking, breath meditation, and the advanced meditative stage with breath suspension in 10 meditative sessions conducted by an experienced meditator. The results (Table 1) show that none of HRV measures of time and frequency domains differed significantly during meditation. In contrast, heart rate and systolic blood pressure reliably decreased as meditation advanced. Because the meditation technique used in this study is close to meditative focusing, the results are concordant with the dharana state described in Telles and colleagues’ study. By using a device to monitor the chest circumstance of the meditator, the current study confirmed that the timing of breath suspension coincided with the subjective experience of breath suspension, complete quiescence, and absence of self-boundary. HRV measures, on the other hand, did not concord with the subjective experience of pure quiescence. Because other authors have argued that HRV is not an index of autonomic control of the circulation, 2 whether HRV can be an ideal index of sympathetic or parasympathetic activities remains questionable. According to the current results, the variations of HRV measures, manifested as the ratio of standard deviation to mean, are much greater than those of heart rate and blood pressure. This has also been shown in previous studies. 1,3,4 According to this view, HRV measures cannot be accurate indexes. The current results suggest that heart rate itself is a better HRV measure for meditation and agree with findings from Mukherjee et al. 5 These authors examined the sensitivity to mental effort and reliability of various HRV measures. Their

Population-Level Impact of the Guidelines Update on Patient Selection and Outcomes After Cardiac Resynchronization Therapy

Data on the time-dependent benefit of cardiac resynchronization therapy with defibrillator (CRT-D) compared with a dual-chamber implantable cardioverter-defibrillator (ICD) to reduce death or ventricular tachycardia (VT) or ventricular fibrillation (VF) are limited. We aimed to evaluate the time-related risk of death or sustained VT or VF in patients receiving CRT-D vs. ICD in the MADIT-RIT trial. Kaplan-Meier survival analyses and multivariate Cox regression models were utilized to compare the incidence and the risk of death or sustained VT/VF in the CRT-D and ICD subgroups by the elapsed time after device implantation (6 months). Of the ICD (n = 742) and CRT-D (n = 757) patients enrolled, the risk of death was lower in CRT-D vs. in ICD early after device implantation [hazard ratio (HR) = 0.42, 95% confidence interval (CI): 0.17-1.03, P = 0.058] and beyond 6 months of follow-up (HR = 0.39, 95% CI: 0.21-0.73, P = 0.004), with the 6-month interaction P = 0.899. The overall risk of sustained VT/VF was reduced in CRT-D vs. ICD patients (HR = 0.73, 95% CI: 0.52-1.03, P = 0.07). However, the risk was similar in the first 6 months (HR = 1.00, 95% CI: 0.62-1.62, P = 0.988), and a lower risk emerged 6 months after CRT-D implantation (HR = 0.58, 95% CI: 0.38-0.88, P = 0.011), with the 6-month interaction P = 0.059. The reduced mortality risk of CRT-D compared with an ICD alone began early after device implantation and was sustained during long-term follow-up; the reduced risk for ventricular tachyarrhythmias did not emerge until 6 months after device implantation. http://clinicaltrials.gov/ct2/show/NCT00947310.

Objective Ethnic and racial disparities in cardiac care may partially result from over-provision of care among white patients. We hypothesized that whites were more likely than blacks and Hispanics to receive cardiac resynchronization therapy with defibrillator (CRT-D) devices outside of ACC/AHA/HRS guidelines. Methods We analyzed 01/2005– 04/2007 data from the ACC-National Cardiovascular Data Registry for implantable cardioverter-defibrillators (ICDs). We identified white, black and Hispanic patients who received CRT-D. We then fit a multivariable hierarchical logistic regression model with full ACC/AHA/HRS guideline concordance (QRS duration >=0.12 ms, LVEF <<26>35%, and class III or IV CHF) as a binary outcome. Independent variables included race/ethnicity, age, gender, cardiomyopathy etiology, duration of CHF, LVEF, blood pressure, QRS duration/morphology, prior coronary revascularization, atrial fibrillation, cerebrovascular disease, hypertension, diabetes, renal failure, and pulmonary disease. Results Of 108,341 registry patients, 39,088 CRT-D recipients were selected, including 33,310 (85%) non-Hispanic whites, 3,963 (10%) non-Hispanic blacks, and 1,815 (5%) Hispanics. Among all CRT-D recipients, univariate analyses indicated 9,430 (24%) patients lacked 1 CRT-D criterion, 1,840 (5%) patients lacked 2 criteria, and 217 (1%) patients lacked all 3 criteria. Specifically, 2,271 (6%) had an LVEF >35%, 6,758 (17%) had class I/II CHF, and 4,732 (12%) had a QRS duration <0.12 ms. In multivariate analyses, blacks (odds ratio [OR] 1.13, 95% confidence interval [CI] 1.04 –1.23; p=0.004) and Hispanics (OR 1.10, 95% CI 0.97–1.24; p=0.13) were more likely to meet all 3 CRT-D eligibility criteria than non-Hispanic whites. Conclusions After multivariate adjustment, we observed greater guideline-concordant use of CRT-D among blacks and Hispanics than among non-Hispanic whites. Although it is possible that patients receiving CRT-D outside of published guidelines had other compelling clinical findings unrecorded in the registry, such as echocardiographic evidence of dyssynchrony, our findings suggest that racial and ethnic differences in CRT-D partially may be due to over-provision of this technology among white patients.

Mid-term feasibility and safety of downgrade procedure from defibrillator to pacemaker with cardiac resynchronization therapy