Parathyroid hormone, calcidiol, calcitriol and adverse events in the acute coronary syndrome.

OBJECTIVE: To know the clinical profile as well as the prognostic significance of elevated levels of parathyroid hormone (PTH) in patients admitted for acute coronary syndrome (ACS).

DESIGN AND SETTING: Observational and prospective study of patients admitted for ACS in a single Spanish center during a period of six months.

INTERVENTION AND VARIABLES OF INTEREST: The circulating concentrations of PTH, calcidiol, calcitriol, NT-proBNP, C-reactive protein, cystatinC and fibrinogen were determined within the first 48h at admission. We performed adjusted models to predict death or re-entry for ACS after hospital discharge.

RESULTS: A total of 161 patients were recruited (age 67±14 years, 75.2% were men). Forty-one (25.5%) patients had elevated PTH values. During follow-up for a period of 275 person-years, 50 adverse events were recorded. Patients with elevated PTH levels were proportionally more women (21.2 vs. 39.0%) and older (63.3 vs. 77.8 years, both P<.05). Likewise, they presented significantly more cardiovascular risk and a worse prognosis during follow-up (incidence rate ratio 2.64 CI 95%: 1.5-4.6). However, in an adjusted model by the GRACE score, PTH levels were not shown to be an independent risk factor (hazard ratio=1.1; 95% CI: 0.6-2.2), neither other components of the panel.

CONCLUSIONS: The proportion of patients with elevated levels of PTH admitted for ACS was high. The presence of high PTH levels was associated with an unfavorable clinical profile and a worse outcome during the follow-up, although it was not an independent predictor of poor prognosis.