Left ventricular myocardial perfusion in patients with hypercholesterolemia during statin therapy

Abstract

Aim: to evaluate the effect of statin therapy on myocardial perfusion assessed with single-photon emission computed tomography (SPECT) with 99mTc-MIBI in asymptomatic patients with severe hypercholesterolemia (HCh).
Materials and Methods: the study included 60 patients with total cholesterol levels >7.5 mmol/L and/or LDL cholesterol >4.9 mmol/L, without clinical signs of ischemic heart disease. All patients, as well as 20 healthy volunteers, underwent myocardial 99mTc-MIBI rest/stress SPECT with CT-attenuation correction. Standard quantitative perfusion parameters (rest/stress/reversibility extents, SRS, SSS, SDS) were evaluated, as well as two new parameters of perfusion defects severity (σsev) or heterogeneity (σhet). The dynamics of initial perfusion impairments and inhomogeneity in patients, receiving statin for 1 year, was compared with noncompliant patients.
Results: quantitative assessment of initial impairments and inhomogeneity of left ventricular myocardial perfusion with SPECT using proposed σsev and σhet parameters reflects expert visual interpretation better than standard parameters. Patients with HCh demonstrate more severe inhomogeneity of MIBI uptake in the LV myocardium, compared with the control group, Rest σhet = 6,5±1,2 and 5,9±0,9, respectively, p<0,01). Positive correlation between Rest σsev/σhet was observed with TCh/LDL-C levels (r=0,33, p<0,01; r=0,37; p<0,01; r=0,29; p=0,02; r=0,32; p=0,01). Connections of perfusion quantitative parameters with HDL-C/TG were not revealed. In compliant group of patients, visual deterioration of LV myocardial perfusion was noted in 18% of cases, in noncompliant group – in 35%, delta of stress σhet parameter was – 0,2±1,6 and 0,7±1,6, respectively (p=0,05).
Conclusion: in patients with severe hypercholesterolemia initial myocardial perfusion impairments or inhomogeneous perfusion is visually observed, which can be quantified using σsev and σhet parameters. Statin therapy provides less pronounced worsening of initial perfusion impairments than in noncompliant patients.