As populations age and become more multimorbid, there is increasing focus on composite measures of health. Frailty is one such example and is defined as a decline in physiological reserve leading to impaired resistance to stressors. There is emerging evidence linking cardiovascular disease and frailty, however the effect of frailty on the structure of the heart is less clearly elucidated.
This study examines the impact of frailty on left ventricular and left atrial structure and function which may provide insights into the mechanistic effect of frailty on cardiovascular disease.
The UK Biobank is a population study examining older adults resident in the United Kingdom. Measurement of frailty was per Fried’s pentad including: physical activity (bottom 20% on International Physical Activity Questionnaire (IPAQ)), weakness (bottom 20% of handgrip strength), unintentional weight loss (self-reported unintentional weight loss over one year), tiredness (self-reported tiredness) and slow gait speed (self-reported usual walking speed). Patients measured as frail in 1-2 markers were categorised as pre-frail; those measured as frail in =3 markers were categorised as frail. Differences in left ventricular and left atrial structure and function between non-frail, pre-frail and frail participants was assessed by multivariable regression adjusting for age, sex, ethnicity, weight and height; effect estimates are presented as percentage change.
After adjustment, pre-frail and frail participants when compared to non-frail participants demonstrated smaller end-diastolic volumes (pre-frail -3.1%, -4.3% to -1.9%; frail -4.7%, -8.0% to -1.2%; p for trend <0.00001), end-systolic volumes (pre-frail -3.2%, -4.8% to -1.5%; frail -5.0%, -9.8% to 0.0%; p for trend = 0.0001), left ventricular mass (pre-frail -3.5%, -4.7% to -2.3%; frail -3.8%, -7.3% to -0.2%; p for trend <0.0001) and left atrial maximal volume (pre-frail -4.1%, -6.2% to -2.1%; frail -7.7%, -13.4% to -1.5%; p for trend <0.00001). There was no change in left ventricular ejection fraction.
Participants determined as pre-frail or frail demonstrate smaller chamber volumes and smaller left ventricular mass than non-frail participants. Traditional cardiovascular risk factors associated with atherosclerosis such as hypertension and high body mass index are associated with larger chambers and high left ventricular mass. This may indicate that the effect of frailty on cardiovascular health may be mediated by processes other than atherosclerosis.