Serum parathyroid hormone and risk of adverse outcomes in patients with stable coronary heart disease

Background and objectiveRecent longitudinal studies have suggested an association of high serum parathyroid hormone levels (PTH) with elevated cardiovascular risk in the general population. This study presents analyses of the prognostic value of baseline PTH for subsequent cardiovascular events and all-cause mortality in a high-risk population with stable coronary heart disease.MethodsBased on measurements of PTH levels in 1133 patients recruited at two German rehabilitation clinics and followed over 8 years, multivariate Cox regression analysis was performed to estimate the risk of secondary cardiovascular events (including myocardial infarction, stroke and death due to cardiovascular diseases) and all-cause-mortality according to PTH quartiles (Q1–Q4) and continuous PTH concentrations.ResultsDuring follow-up, 153 cardiovascular events and 124 deaths occurred. Age and sex-adjusted Cox regression analysis yielded statistically significant positive associations of PTH with both cardiovascular event incidence and all-cause mortality (HR (95% CI) per SD increase of PTH: 1.35 (1.21–1.51) and 1.25 (1.11–1.42), respectively). Associations remained essentially unchanged after additional adjustment for multiple cardiovascular risk factors. More detailed dose–response analyses showed strong risk elevation for above-normal levels of PTH (>95th percentile), with essentially no association at lower levels.ConclusionThe results of this first detailed study in a cohort of patients with stable coronary heart disease suggest an independent predictive value of above-normal PTH for the prognosis in patients with stable coronary heart disease.