Do patients with heart failure with reduced ejection fraction due to nonischemic etiology eligible for cardiac resynchronization therapy CRT benefit from an implantable cardioverter-defibrillator ICD? The primary outcome was all-cause mortality, and secondary outcomes were the combination of cardiovascular mortality or heart failure hospitalization and sudden cardiac death. Utilizing an extensively phenotyped group of primary prevention CRT-D recipients, we found the variables increasing the risk for HF hospitalization were distinct from those associated with an increased risk of VAs.
By synthesizing these observations into risk score model constructs, we were able to identify a group of patients with high risk for HF hospitalization and low risk for VAs. In fact, 23 8. They represent a sub-group of patients at very low risk of arrhythmic events IR 1 per person-years and high risk of HF progression IR 23 per person-years that may potentially not derive incremental survival benefit from ICD therapy.
Patients with atrial fibrillation were excluded from most CRT trials with the exception of the RAFT trial, which in a post-hoc analysis failed to show benefit from CRT in this particular sub-group [ 17 ]. This has been further corroborated by several other observational studies [ 18 , 19 ].
Additionally, a dose-response effect has been described relating the burden of atrial fibrillation to adverse outcomes in CRT patients [ 20 ]. Whether anemia is a marker of poor baseline function or a direct contributor to HF morbidity and mortality has not yet been clearly elucidated [ 22 ]. Circulating cytokines are elevated in HF and contribute to the overall pro-inflammatory state. IL6 has been shown to be an independent predictor of HF morbidity and mortality [ 23 , 24 ] as well as implicated in the development of anemia of chronic disease in HF patients [ 25 ].
A role for inflammatory cytokines including HS-CRP in the prediction of ventricular arrhythmia risk has been previously described in the literature [ 27 ]. We have previously shown in a sub-population of our cohort who underwent contrast enhanced cardiac magnetic resonance imaging that the presence of heterogeneous myocardial tissue gray zone and elevated HS-CRP are the only two independent predictors of appropriate ICD shock [ 9 ].
As mentioned earlier, anemia is a common comorbid condition with HF that portends adverse survival. Hence, it is not surprising that reported outcomes of patients with CRT-P vs. CRT-D in these studies are conflicting. Furthermore, in non-responders no survival benefit was witnessed at any of the follow-up times [ 29 ]. However, rates of the different pre-specified endpoints have been reported for each of the CRT arms despite no accompanying formal comparative statistical testing.
There are several limitations affecting this analysis. However, the findings from our analysis align with prior studies of larger groups of patients. Nevertheless, validation of these findings will be necessary in larger populations. With that said, the median rate of VAs resulting in defibrillator therapy was bpm interquartile range, — which reflects a predominance of ICD therapy for fast life-threatening VAs. In addition, there was no significant difference in programming strategies between patients who received appropriate ICD therapy and those who did not.
Third, serum biomarkers were only measured at baseline and may not accurately reflect the levels around the time of ICD therapy or HF hospitalization.
The study design mandated that patients at the time of enrollment did not have an acute illness in the hope of having baseline inflammatory markers reflective of chronic levels. Fourth, optimal guideline directed medical therapy for heart failure at maximal tolerated doses was encouraged in our study but data on drug dosing was unfortunately not collected.
Finally, our relatively small sample size did not allow us to perform a stratified analysis by the underlying cause of cardiomyopathy. HF is a complex syndrome orchestrated by multiple complex and overlapping pathways that can result in modes of death secondary to pump failure or VAs. Refining the risk of either of these endpoints in patients with dyssynchronous heart failure would improve guidance on the type of CRT system that stands to result in greatest patient benefit.
Further validation of our findings in larger cohorts is needed to ensure generalizability and facilitate adoption of our models in clinical practice. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. National Center for Biotechnology Information , U. PLoS One. Published online Apr 7. Ellenbogen , 4 Eliseo Guallar , 2 Gordon F. Joseph E.
Kenneth A. Gordon F. Ali A. Sovari, Editor. Author information Article notes Copyright and License information Disclaimer. Jude Medical for participation in fellows educational programs and advisory councils. AC is currently employed by Medtronic as their VP of clinical research for defibrillators.
Jude Medical. Funding acquisition: AC GT. Project administration: VN AC. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation.
Volume Article Contents. Nyolczas , N. Oxford Academic. Google Scholar. Heart Rhythm. Among patients with nonischemic cardiomyopathy who require cardiac resynchronization therapy, a pacemaker may have comparable efficacy and more cost efficiency compared with a defibrillator, according to findings published in HeartRhythm. The primary outcome was all-cause mortality, with secondary outcomes including first cardiac hospitalization and total medical costs.
Propensity score matching and Cox proportional hazard models were used to balance patient characteristics between treatment groups, Saba and colleagues wrote. According to Saba and colleagues, their data support greater use of CRT-P in patients, as it is associated with reduced costs and comparable outcomes.
0コメント