Geriatric Conditions in Patients Undergoing Defibrillator Implantation for Prevention of Sudden Cardiac Death: Prevalence and Impact on Mortality

Abstract

Background: Geriatric conditions may influence outcomes among patients receiving implantable cardioverter-defibrillators (ICDs). We sought to determine the prevalence of frailty and dementia among older adults receiving primary prevention ICDs and to determine the impact of multimorbidity on mortality within 1 year of ICD implantation.

Methods and results: The cohort included 83 792 Medicare patients from the National Cardiovascular Data Registry ICD Registry who underwent first primary prevention ICD implantation between 2006 and 2009. These data were merged with Medicare analytic files to determine the prevalence of frailty, dementia, and other conditions before ICD implantation, as well as 1-year mortality. A validated claim-based algorithm was used to identify frail patients. Mutually exclusive patterns of chronic conditions were examined. The association of each pattern with 1-year mortality was assessed using logistic regression models adjusted for selected patient characteristics. Approximately 1 in 10 Medicare patients with heart failure receiving a primary prevention ICD had frailty (10%) or dementia (1%). One-year mortality was 22% for patients with frailty, 27% for patients with dementia, and 12% in the overall cohort. Several multimorbidity patterns were associated with high 1-year mortality rates: dementia with frailty (29%), frailty with chronic obstructive pulmonary disease (25%), and frailty with diabetes mellitus (23%). These patterns were present in 8% of the cohort.

Conclusions: More than 10% of Medicare beneficiaries with heart failure receiving primary prevention ICDs have frailty or dementia. These patients had significantly higher 1-year mortality than those with other common chronic conditions. Frailty and dementia should be considered in clinical decision-making and guideline development.

Keywords: Medicare; defibrillators, implantable; dementia; geriatrics; pulmonary disease, chronic obstructive.

Figure 1

Flow diagram of the study population.

Figure 2

MST=metastatic solid tumor; CKD=chronic kidney disease; CVA=cerebrovascular accident; COPD=chronic obstructive pulmonary disease.

Figure 3

^* Because our sorting and ranking step had confirmed that many of the patterns with high one-year mortality included frailty or dementia, and because these were the geriatric conditions of interest, we first classified patients into a multimorbidity pattern based on the presence of one of these two geriatric conditions. Patients who did not have dementia or frailty were placed into another multimorbidity pattern based on their individual combination of building block conditions. ^† Each row is a distinct pattern. Shading identifies which comorbidities comprise the pattern. Each pattern does include the comorbidity shaded in black, and may include any of the other comorbidities in that row shaded in gray. For example, all individuals represented in row 2 have dementia, but any individual in row 2 may also have the conditions shaded in gray. Individuals in row 7 have either cirrhosis, metastatic solid tumor, hyponatremia, or a combination of these three comorbidities and no others. ^‡ COPD = chronic obstructive pulmonary disease. CKD = chronic kidney disease. CVA = cerebrovascular disease.

Figure 4

MST=metastatic solid tumor; CKD=chronic kidney disease; CVA=cerebrovascular accident; COPD=chronic obstructive pulmonary disease. Size of bubble corresponds to odds ratio, calculated using adults with heart failure alone as referent (odds if have heart failure and multimorbidity pattern/odds if have heart failure alone). Models adjusted for age, gender, left ventricular ejection fraction, atrial fibrillation/flutter, systolic blood pressure, and New York Heart Association functional classification.