Association between traditional cardiovascular risk factors and mortality in the oldest old: untangling the role of frailty

BACKGROUND: To date, there is no consensus regarding cardiovascular risk management in the very old. Studies have shown that the relationship between traditional cardiovascular risk factors and mortality is null or even inverted within this age group. This relationship could be modified by the presence of frailty. This study was performed to examine the effect of frailty on the association between cardiovascular risk factors and mortality in the oldest old. METHODS: The BELFRAIL study is a prospective, observational, population-based cohort study of 567 subjects aged 80 years and older. Data on cardiovascular risk factors were recorded. Frailty was assessed using three different models: the Groningen Frailty Indicator, Fried and Puts models. Participants were considered robust if they were ‘not frail’ according to all three models, and frail if they met the frailty criteria for one of the three models. The follow-up data on mortality and cause of death were registered. RESULTS: No cardiovascular risk factor was associated with mortality in subjects with and without cardiovascular disease. The presence of frailty was a strong risk factor for mortality [HR: 2.5, 95%CI: (1.9–3.2) for all-cause mortality; HR: 2.2, 95%CI: (1.4–3.4) for cardiovascular mortality]. In robust patients, a history of cardiovascular disease increased the risk for mortality [HR: 1.7, 95%CI: (1.1–2.5) for all-cause mortality; HR: 2.2, 95%CI: (1.2–3.9) for cardiovascular mortality]. In frail patients, there was no association between any of the traditional risk factors and mortality. CONCLUSIONS: Traditional cardiovascular risk factors were not associated with mortality in very old subjects. Frailty was shown to be a strong risk factor for mortality in this age group. However, frailty could not be used to identify additional subjects who might benefit more from cardiovascular risk management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12877-017-0626-x) contains supplementary material, which is available to authorized users.