Fo ATP synthase C subunit serum levels in patients with ST-segment Elevation Myocardial Infarction: Preliminary findings

Background Recent studies in cell cultures hypothesized that the long-sought molecular pore of the mitochondrial permeability transition pore could be the Fo ATP synthase C subunit (Csub). We assessed Csub in patients with ST-segment elevation myocardial infarction (STEMI) and if it is associated with surrogate endpoints of myocardial reperfusion. Methods We enrolled 158 first-time acute anterior STEMI treated with successful percutaneous coronary intervention (PCI). Csub was measured, after the procedure, in serum by ELISA. Csub values were related to thrombolysis in myocardial infarction (TIMI) myocardial perfusion grade (TMPG), TIMI frame count (TFC), ST-segment resolution and cardiac marker release. Echocardiography and clinical outcome were recorded at 6 months. Results Csub was detectable in serum and it was not normally distributed (6.3% [4–9.3%]). Csub values were higher in patients with poor values of TMPG and TFC (p = 0.002 and p = 0.001, respectively). Csub values were higher in patients with absent or partial ST-segment resolution as compared to those with complete ST-segment resolution (p < 0.0001 and p = 0.003, respectively). After adjustment for potential confounding factors, Csub emerged as an independent determinant of absent ST-segment resolution (HR 1.8, 95% CI 1.5–2.3, p = 0.007), TMPG 0–1 (HR 1.7, 95% CI 1.3–2.5, p = 0.01) and TFC above the median value (HR 1.5, 95% CI 1.3–2.1, p = 0.03). Left ventricle ejection fraction, wall motion score index and cumulative incidence of death and heart failure were worse in patients with elevated Csub. Conclusions Our study is the first evidence that Csub is detectable in STEMI patients and that it is significantly related to several surrogate markers of myocardial reperfusion.