ClinicalDevicesComparison of left ventricular lead upgrade vs continued medical care among patients eligible for cardiac resynchronization therapy at the time of defibrillator generator replacement: Predictors of left ventricular lead upgrade and associations with long-term outcomes
Introduction
Conduction system disease may develop during the clinical course of patients with cardiomyopathies.1 The treatment of these conduction abnormalities along with associated dyssynchrony using cardiac resynchronization therapy (CRT) improves survival, left ventricular (LV) function, and symptoms in subsets of patients with heart failure (HF).2, 3, 4 For those patients who do not qualify for CRT but have persistently depressed LV function, an implantable cardioverter–defibrillator (ICD) provides protection from sudden arrhythmic death.5 Importantly, conduction disease may develop over time, and patients who initially qualify for an ICD without CRT may later develop an indication for resynchronization.6 In these CRT-eligible patients with a pre-existing, non-CRT ICD, clinical decision-making is unclear. Specifically, how do the benefits and risks compare in CRT-eligible patients with a pre-existing ICD who are treated with an LV lead upgrade procedure vs CRT-eligible patients who continue on medical therapy with an ICD generator replacement but without LV lead upgrade.
Published evidence to guide clinical decision-making regarding CRT upgrade in a population with pre-existing ICD is limited. No randomized clinical trials have evaluated whether CRT upgrade confers the same benefits that have been observed with de novo CRT implantation. Furthermore, the major trials evaluating the benefit of CRT specifically excluded patients with a pre-existing device. A registry examined periprocedural morbidity of LV lead upgrade but without a CRT-eligible control population and with little information about long-term outcomes.7 Other studies examined LV lead upgrade outcomes but lacked a comparator group of pre-existing ICD patients who did not undergo CRT upgrade.8,9 By examining the National Cardiovascular Data Registry (NCDR) ICD Registry, a large, real-world population of patients implanted with an ICD, we sought to assess the prevalence and predictors of CRT upgrade in CRT-eligible patients undergoing ICD generator replacement. We also sought to assess the association of CRT upgrade vs continued medical care (ICD generator replacement only) with subsequent clinical outcomes, including procedural complications, rehospitalization, and mortality.
Section snippets
Data sources
Patient data were derived from the American College of Cardiology’s (ACC) NCDR ICD Registry. The NCDR ICD Registry uses a data collection form with standardized data elements and definitions to capture patient demographics, medical history, discharge medication prescription, and other diagnostic study results and adverse events. Longitudinal outcomes (beyond the index hospitalization) were obtained by linking the registry data to Medicare inpatient fee-for-service claims using indirect patient
Results
Between April 1, 2010, through December 31, 2014, a total of 751,791 patients presented for an ICD-related procedure at hospitals in the United States. Of these patients, 165,981 were admitted for elective generator replacement, LV lead upgrade, or device relocation of their non-CRT ICD. Within this group, 18,223 patients were eligible for CRT as defined by LVEF <35%, QRS >120 ms, and NYHA functional class III/IV HF. Patients with a pacemaker (n = 1495), epicardial lead (n = 803), or abdominal
Discussion
In a large, national cohort of patients with a pre-existing ICD, 75.5% of CRT-eligible patients underwent device upgrade with an 11.2% LV lead failure rate. Although younger patients with lower LV ejection fractions and nonischemic cardiomyopathy were more likely to undergo CRT upgrade, the presence of a left bundle branch block was most predictive (OR 4.6; 95% CI 4.1–5.1; P <.0001). CRT upgrade was associated with a long-term reduction in mortality. CRT upgrade did not significantly impact
Conclusion
In a real-world, national registry of CRT-eligible patients with a pre-existing ICD, upgrade to CRT was associated with lower rates of mortality compared to continued medical management with ICD generator replacement only. This reduction in mortality did not come at the clinical cost of increased periprocedural morbidity, although there was no impact on rates of hospitalization that has been observed in many CRT clinical trials. Further trials with randomized populations should be completed to
References (17)
- et al.
ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices) developed in collaboration with the American Association for Thoracic Surgery and Society of Thoracic Surgeons
J Am Coll Cardiol
(2008) - et al.
Linking inpatient clinical registry data to Medicare claims data using indirect identifiers
Am Heart J
(2009) - et al.
Prevalence and predictors of off-label use of cardiac resynchronization therapy in patients enrolled in the National Cardiovascular Data Registry Implantable Cardiac-Defibrillator Registry
J Am Coll Cardiol
(2010) - et al.
Comparative long-term outcomes after cardiac resynchronization therapy in right ventricular paced patients versus native wide left bundle branch block patients
Heart Rhythm
(2016) - et al.
Hemiblocks revisited
Circulation
(2007) - et al.
Cardiac resynchronization in chronic heart failure
N Engl J Med
(2002) - et al.
Cardiac-resynchronization therapy with or without an implantable defibrillator in advanced chronic heart failure
N Engl J Med
(2004) - et al.
The effect of cardiac resynchronization on morbidity and mortality in heart failure
N Engl J Med
(2005)
Cited by (0)
Funding sources: This work of Drs Hyman and Marchlinski was supported by the J and J Fund in Electrophysiology. This research was also supported by the American College of Cardiology Foundation’s National Cardiovascular Data Registry (NCDR). Disclosures: Dr Curtis receives salary providing analytic services to the NCDR; and has equity interest in Medtronic. Dr Hsu has received honoraria from Medtronic, Boston Scientific, Abbott, Biotronik, Biosense Webster, Pfizer, and Bristol-Myers Squibb; research grants from Biotronik and Biosense Webster; and has equity in Acutus Medical. Dr Marchlinski has received consulting fees from Abbott, Biosense Webster, Biotronik, Boston Scientific, and Medtronic. Dr Minges receives salary providing analytic services to the NCDR. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.