Perioperative Modulation of Left Ventricular Systolic Performance: A Retrospective Study on Ionized Calcium and Vitamin D in Cardiac Surgery Patients

TL;DR

This study found that preoperative vitamin D levels may influence heart function in cardiac surgery patients, while changes in calcium levels did not show a clear link.

Contribution

The study is the first to explore the perioperative impact of ionized calcium and vitamin D on left ventricular performance in cardiac surgery.

Findings

Preoperative vitamin D levels were significantly lower in patients with reduced ejection fraction.

Postoperative ejection fraction was inversely associated with vasoactive inotropic scores and ICU stay.

Changes in ejection fraction correlated with longer cardiopulmonary bypass and mechanical ventilation times.

Abstract

Background: The perioperative impact of calcium and vitamin D on left ventricular (LV) performance during major cardiac surgery remains unexplored. We aimed to assess the relation of calcium and vitamin D measured at different time points with the LV ejection fraction (EF), and to investigate whether changes in EF correlate with postoperative outcomes. Methods: We enrolled 83 patients, in whom ionized calcium was measured before, during, and after surgery (until discharge), vitamin D preoperatively, and EF pre- and postoperatively at 24 h. The postoperative outcomes were cardiopulmonary bypass (CPB) time, aortic cross-clamp time, mechanical ventilation time, vasoactive inotropic score (VIS) (intraoperative, day 0, day 1), and ICU stay time. Results: The mean age was 64.9 ± 8.5 years, with 21 of the patients (25%) having an EF < 50%. The median change from preoperative to postoperative EF was −2.0 (−10.0–0.0) % (p < 0.001). At the baseline, the EF < 50% group had significantly lower preoperative vitamin D levels than the EF ≥ 50% group (p = 0.048). The calcium trend did not differ across the groups. Preoperative EF was significantly associated with CPB time (r = 0.22, p = 0.044) and aortic cross-clamp time (r = 0.24, p = 0.031). Postoperative EF was significantly and inversely associated with intraoperative VIS (r = −0.28, p = 0.009), VIS day 0 (r = −0.25, p = 0.020), VIS day 1 (r = −0.23, p = 0.036), and ICU length of stay (r = −0.22, p = 0.047). Finally, the change in ejection fraction was significantly and inversely associated with CPB time (r = −0.23, p = 0.037), aortic cross-clamp time (r = −0.22, p = 0.044), intraoperative VIS (r = −0.42, p < 0.001), VIS day 0 (r = −0.25, p = 0.024), mechanical ventilation time (r = −0.22, p = 0.047), and ICU length of stay (r = −0.23, p = 0.039). Conclusions: The fluctuations in perioperative ionized calcium levels were not associated with the evolution of LVEF, although preoperative vitamin D levels may affect those with low EF. Correspondingly, a reduced EF significantly impacted all the studied postoperative outcomes. Further investigation into biomarkers affecting cardiac inotropic function is warranted to better understand their significance.

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