Clinical Significance of Biological Age in Patients Undergoing Percutaneous Coronary Intervention

Objective: To test whether biological age calculated using deficits, functional impairments, or their combination will provide improved estimation of long-term mortality among older adults undergoing percutaneous coronary intervention. Patients and Methods: Cardiovascular deficits, noncardiovascular deficits, and functional impairments were prospectively studied in 535 patients aged 55 years or older from August 1, 2014, to March 31, 2018. Models for biological age included deficits (acquired, increase with age, associated with worse prognosis, did not saturate early), functional impairments (subjective—help with daily activities, difficulty with sensory input, continence, weight, balance, mobility; or objective—timed up and go, functional reach), or their combination. Results: The mean ± SD age of the study patients was 72.1±9.5 years. For every 5-year increase in chronological age, the mean number of cardiovascular deficits increased from 2.36 among patients younger than 70 years to 3.44 in nonagenarians. The mean number of functional impairments increased from 2.15 for those younger than 70 years to 6.74 for nonagenarians. During a median follow-up of 2.05 years, 99 patients died. Significant improvement in the Harrell concordance index (C index) for prediction of long-term all-cause mortality was noted with biological age calculated from deficits and impairments compared with chronological age (0.77 vs 0.65; P<.001) and when estimating biological age via functional impairments alone vs chronological age (0.75 vs 0.65; P<.001) but not via deficits alone (0.71 vs 0.65; P=.08). Biological age estimates from subjective functional impairments captured most of the prognostic information related to all-cause and noncardiac mortality, whereas deficit-based estimation favored cardiovascular mortality. Conclusion: The derivation of biological age from deficits and functional impairments provides a major improvement in the estimation of survival as estimated by chronological age.