Prognostic value of renal function in patients with cardiac resynchronization therapy.
ABSTRACT Renal insufficiency is prevalent in patients with heart failure and indicates poor prognosis. We examine (i) the relationship between left ventricular (LV) reverse remodeling (RR) and renal function and (ii) the prognostic value of renal function in patients receiving cardiac resynchronization therapy (CRT).
The relationship between LV-RR, defined as a 10% reduction in LV end-systolic volume, and renal function was examined in 85 consecutive patients receiving CRT. Echocardiographic assessment and renal function tests were performed before and 3 months after CRT. All-cause mortality and the composite of mortality or heart failure hospitalization between those with preserved or deteriorated renal function at 3 months were assessed by Kaplan Meier analysis.
There was a slight improvement in glomerular filtration rate (GFR) in those with LV-RR (n=44; 51.7+/-20.4 vs. 54.2+/-19.1 ml/min/1.73 m2; p=0.024) while a significant deterioration (n=41; 61.9+/-17 vs. 48.8+/-13.0 ml/min/1.73 m2; p<0.001) was observed in those without LV-RR. The change (Delta) in GFR was significantly correlated with DeltaLV end-systolic/diastolic volumes and DeltaLV ejection fraction. After follow up of 856.4+/-576.8 days, patients with preserved renal function had significant lower all-cause mortality (log rank chi2=4.82, p=0.029) and the composite endpoints (log rank chi2=5.04, p=0.025).
Preservation of renal function was observed in patients with systolic heart failure and renal insufficiency responding to CRT and provided prognostic information. A rapid decline in renal function after CRT was associated with worse clinical outcomes.
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ABSTRACT: A decade of research has established the role of cardiac resynchronization therapy (CRT) in medically refractory, moderate to severe systolic heart failure (HF) with intraventricular conduction delay. CRT is an electrical therapy instituted to reestablish ventricular synchronization in order to improve cardiac function and favorably modulate the neurohormonal system. CRT confers a mortality benefit, improved HF hospitalizations, and functional outcome in this population, but not all patients consistently demonstrate a positive CRT response. The nonresponder rate varies from 20% to 40%, depending on the defined response criteria. Efforts to improve response to CRT have focused on a number of fronts. Methods to optimize the correction of electrical and mechanical dyssynchrony, which is the primary target of CRT, has been the focus of research, in addition to improving patient selection and optimizing post-implant care. However, a major issue in dealing with improving nonresponse rates has been finding an accurate and generally accepted definition of "response" itself. The availability of a standard consensus definition of CRT response would enable the estimation of nonresponder burden accurately and permit the development of strategies to improve CRT response. In this review, we define various aspects of "response" to CRT and outline variability in the definition criteria and the problems with its inconsistencies. We describe clinical, laboratory, and pacing predictors that influence CRT response and outcome and how to optimize response.Journal of Cardiovascular Translational Research 04/2012; 5(2):196-212. · 3.06 Impact Factor
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ABSTRACT: BACKGROUND: Octogenarians (>80 years) have been underrepresented in clinical trials of cardiac resynchronization therapy (CRT). OBJECTIVE: To determine the benefit of CRT with or without a defibrillator in older elderly patients. METHODS: We retrospectively studied consecutive patients who received CRT at our institution from 2002 through 2008. New York Heart Association (NYHA) class and echocardiographic parameters were assessed before and after CRT. Thirty-day complications after device implant were collected. Survival data were obtained from the national death and location database. Data were compared between those 80 years and younger and those older than 80 years. RESULTS: Of 728 patients identified, 90 (12.4%) were older than 80 years. After CRT, older and younger patients had similar improvements in NHYA class (P = 0.41), ejection fraction (P = 0.48), and mitral valve regurgitation (MR) severity (P = 0.42). In the older patients, defibrillator implantation was associated with comparable improvement in NYHA class, ejection fraction, and MR grade severity (P > 0.05), as in those without a defibrillator. Overall survival was worse in octogenarians than in the younger patients by Kaplan-Meier estimates (P = 0.001). Multivariate analysis showed similar survival between the younger and older subjects (hazard ratio, 1.23; 95% confidence interval, 0.83-1.84; P = 0.31). The observed complication rate in all study subjects was 12.2%, with no difference between the two age groups. CONCLUSION: Octogenarian patients who received CRT with or without a defibrillator for advanced heart failure had similar clinical benefits as younger patients. CRT should not be withheld from octogenarians meeting current selection guidelines.Pacing and Clinical Electrophysiology 12/2012; · 1.75 Impact Factor
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ABSTRACT: BACKGROUND: Cardiac resynchronization therapy (CRT) confers morbidity and mortality benefits to selected patients with heart failure. This systematic review examined effects of CRT in CKD patients (estimated GFR [eGFR] <60 ml/min per 1.73 m(2)). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: MEDLINE and Scopus (from 1990 to December 2012) and conference proceedings abstracts were searched for relevant observational studies and randomized controlled trials (RCTs). Studies comparing the following outcomes were included: (1) CKD patients with and without CRT and (2) CKD patients with CRT to non-CKD patients with CRT. Mortality, eGFR, and left ventricular ejection fraction data were extracted and pooled when appropriate using a random-effects model. RESULTS: Eighteen studies (14 observational studies and 4 RCTs) were included. There was a modest improvement in eGFR with CRT among CKD patients (mean difference 2.30 ml/min per 1.73m(2); 95% confidence interval, 0.33 to 4.27). Similarly, there was a significant improvement in left ventricular ejection with CRT in CKD patients (mean difference 6.24%; 95% confidence interval, 3.46 to 9.07). Subgroup analysis of three RCTs reported lower rates of death or hospitalization for heart failure with CRT (versus other therapy) in the CKD population. Survival outcomes of CKD patients (compared with the non-CKD population) with CRT differed among observational studies and RCTs. CONCLUSIONS: CRT improves left ventricular and renal function in the CKD population with heart failure. Given the increasing use of cardiac devices, further studies examining the effects of CRT on mortality in CKD patients, particularly those with advanced kidney disease, are warranted.Clinical Journal of the American Society of Nephrology 05/2013; · 5.07 Impact Factor