Clinical Registries in Geriatric Cardiology: Speaking to the Clinical Trial Silence
Randomized controlled clinical trials (RCT) are a cornerstone of clinical research and remain the gold standard for isolating the independent impact of an intervention.1 However, in the field of geriatrics and geriatric cardiology, RCTs contribute little insight for most interventions. Since most trial enrollment criteria exclude elderly patients and/or those with multiple comorbidities, their conclusions are often unable to be extrapolated to these populations, leaving them and their providers at a loss for optimal management strategies.
However, the growing number and size of clinical registries and electronic health data repositories provides a potential path forward. This data, by definition, captures care as it is delivered and can thus characterize geriatric patient populations, their care patterns, and any subsequent outcomes—good and bad alike.2 By systematically studying these relationships, the provider community can gain insight into potentially beneficial or deleterious treatments for these patients.
Cardiology has led the way in the development and analysis of clinical registries. For example, both the American College of Cardiology (ACC) and American Heart Association (AHA) have established robust and massive datasets that characterize the cardiac care and outcomes for significant portions of the population. The ACC oversees the National Cardiovascular Data Registry (NCDR) program, a collection of clinical registries that encompass various acute (e.g., myocardial infarction) and chronic (e.g., congestive heart failure) conditions.3,4 In addition, the NCDR also collects information on a variety of cardiovascular procedures (e.g., percutaneous coronary intervention [PCI], implantable cardioverter-defibrillator implantation, and transcatheter aortic valve replacement). The AHA maintains the Get With The Guidelines (GWTG) program, a suite of quality improvement and data registry efforts for both acute and chronic cardiovascular conditions.5 Large health systems, such as the Veterans Health Administration (VHA), also contain significant amounts of "real world" cardiac care and outcomes information. For example, the VHA Clinical Assessment, Reporting, and Tracking (CART) program collects patient and procedural information for all 79 VHA cardiac catheterization laboratories.6
Importantly, all of these data collection efforts are broadly inclusive of age and comorbidity. As a result, they can provide important insights into the care and outcomes of geriatric cardiac patients. For example, research into the comparative effectiveness of stent type and outcomes of carotid endarterectomy in the elderly has been conducted using NCDR data.7-11 Outcomes in elderly survivors of in-hospital cardiac arrest and trends in the use of coronary artery disease preventative medications among the elderly have been characterized using the GTWG data.11,12 Safety and outcomes of PCI among nonagenarians was recently published using the VHA CART data.13 These and other studies point to the potential of registry data to provide better insight into optimal care of geriatric patients.
Despite this promise, clinical registry research has significant limitations. Confounding and bias due to differential treatment allocation can confuse the association between care and outcomes and provide misleading information about its efficacy. Although high-quality studies use sophisticated statistical techniques to minimize this risk, it can never be completely eliminated. As a result, caution should always be employed in applying registry research findings to clinical care. Registries also typically lack important symptom and outcome data. For example, measures of frailty, symptoms, and other measures of biologic reserve—all of which are both important mediators of disease and outcomes of therapeutic interventions—are rarely collected in clinical registries. This is particularly germane to geriatric populations, given the relatively higher importance of maintaining satisfactory quality of life, rather than longevity, in these patients. Promising early work in enhancing registries with patient-reported outcomes is underway, but current data does not provide insight into these important variables.14
Nonetheless, clinical registries are essential tools in the characterization and care of geriatric cardiac patients. Thoughtful and rigorous registry research should target precise patient populations for study (e.g., patients older than 90 years, patients with multiple comorbidities that require discordant medication regimens) to provide better insight into management strategies and their associated outcomes. For example, research analyzing the impact of various medication dosing regimens and their associated outcomes and safety would address a vitally important clinical issue for these patients. These studies could also provide trialists with potential hypotheses for future trial enrollment that specifically target these vulnerable populations.15
Although RCTs will always be necessary to provide the final word in intervention efficacy, clinical registries and other forms of "real world" clinical data are a complementary and essential tool to better understand the optimal care of geriatric cardiology patients. Both clinicians and their investigator counterparts should continue to advocate for their thoughtful development and use.
- Ho PM, Peterson PN, Masoudi FA. Evaluating the evidence: is there a rigid hierarchy? Circulation 2008;118:1675-84.
- Bufalino VJ, Masoudi FA, Stranne SK, et al. The American Heart Association's recommendations for expanding the applications of existing and future clinical registries: a policy statement from the American Heart Association. Circulation 2011;123:2167-79.
- Brindis RG, Fitzgerald S, Anderson HV, Shaw RE, Weintraub WS, Williams JF. The American College of Cardiology-National Cardiovascular Data Registry (ACC-NCDR): building a national clinical data repository. J Am Coll Cardiol 2001;37:2240-5.
- Messenger JC, Ho KK, Young CH, et al. The National Cardiovascular Data Registry (NCDR) Data Quality brief: the NCDR Data Quality Program in 2012. J Am Coll Cardiol 2012;60:1484-8.
- Hong Y, LaBresh KA. Overview of the American Heart Association "Get With the Guidelines" programs: coronary heart disease, stroke, and heart failure. Crit Pathw Cardiol 2006;5:179-86.
- Maddox TM, Plomondon ME, Petrich M, et al. A national clinical quality program for Veterans Affairs catheterization laboratories (from the Veterans Affairs Clinical Assessment, Reporting, and Tracking program). Am J Cardiol 2014;114:1750-7.
- Kutcher MA, Brennan JM, Rao SV, et al. Comparative effectiveness of drug-eluting stents on long-term outcomes in elderly patients trea
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