Hip fracture may lead to immediate death in older adults with CHD

Older adults with prevalent coronary heart disease (CHD) who sustain an osteoporotic hip fracture have a very high risk of immediate death, as well as increased long-term risk, according to a study.

The short- and long-term posthip fracture mortality rates are higher in people with CHD than in those with CHD who had a first episode of heart failure (HF) but no hip fracture. In individuals with no CHD, the risk of death from a hip fracture is similar to that associated with a first episode of HF.

“As a case study in the absolute effects of a comorbidity on posthip fracture mortality, hip fracture in a person with CHD carries an exceedingly high mortality rate, even higher than that following incident HF in individuals with CHD,” the researchers said.

The rate of mortality following a hip fracture among older adults without CHD was 21.83 per 100 person-years, including 49.27 per 100 person-years in the first 6 months after a hip fracture. Among those with prevalent CHD, the mortality rates were much greater at 32.52 and 79.44 per 100 person-years, respectively. [Am J Med 2023;136:789-795.E2]

Additionally, individuals with prevalent CHD and incident HF but no hip fracture had postincident HF mortality rates of 25.62 per 100 person-years overall and 46.4 per 100 person-years in the first 6 months.

The hazard ratio for mortality was likewise increased in all three groups: five- to sevenfold at 6 months and 1.7- to 2.5-fold beyond 5 years.

These findings are consistent with those of large cohort studies and meta-analysis that also reported increased rates and relative risks of mortality. [Ann Intern Med 2010;152:380-390; Am J Epidemiol 2019;188:398-407; Osteoporos Int 2007;18:1463-1472; J Intern Med 2017;281:300-310; Osteoporos Int 2009;20:1633-1650]

Studies examining cardiovascular disease (CVD) or CHD with respect to mortality after a hip fracture are few. One study from the US found a threefold increase in 30-day mortality following a hip fracture in people with a history of cardiac disease, while another from the UK did not find any association between prevalent CVD and mortality. [Int Orthop 2013;37:2119-2124; BMJ 2005;331:1374]

“How or why hip fractures are associated with an immediate increase in mortality is uncertain, as surgical mortality of hip fractures may be as low as 1 percent to 2 percent,” the researchers said. “Venous thromboembolism, pneumonia, decreased mobility, gastrointestinal haemorrhage, and difficulty with self-care are all likely to contribute.” [Int J Surg 2018;54:316-327]

Furthermore, previous studies have shown that hip fractures occur in association with albuminuria, cardiovascular autonomic neuropathy, elevated levels of advanced glycation end products, and with carotid artery atherosclerosis in the absence of CVD. [Osteoporos Int 2013;24:2993-3000; Arch Osteoporos 2021;16:163; J Bone Miner Res 2014;29:1061-1066; Osteoporos Int 2018;29:2219-2230]

“It is possible that inflammation and other unmeasured factors associated with an acute hip fracture exacerbate these factors, leading to early mortality,” the researchers said.

In the current study, 4,092 older adults without CHD and 1,173 with prevalent CHD were evaluated. Poisson models and hazard ratios with Cox regression were used to measure mortality rates following a hip fracture. The researchers also compared the mortality rates among participants with prevalent CHD who had either a hip fracture or incident HF but no hip fracture.

“Major limitations of this study include not being able to reupdate all covariables at the time of each hip fracture, although CHD was continuously ascertained,” the researchers said. “Hence, we could not determine the confounding effects of comorbidities that may have co-occurred with hip fracture itself.”