Silent severe myocardial ischemia in a past illicit drug user imaged with myocardial perfusion scintigraphy

Myocardial Perfusion Imaging and C-Reactive Protein in Myocardial Ischemia: A Retrospective Single-Center Study

BACKGROUND

Inflammation is an important mechanism in atherosclerosis and plaque formation. C-reactive protein (CRP) is a common inflammatory biomarker associated with the risk of coronary heart disease. We investigated the relationship of CRP with findings from myocardial perfusion imaging (MPI).

METHODS

In this retrospective study, 102 consecutive patients (mean age 71 years, 68% males) who underwent MPI (for diagnostic reasons or quantification of myocardial ischemia) and CRP determination (upper limit: 6 mg/L) within 1 month from MPI were included. The patients had no infection or recent acute coronary syndrome.

RESULTS

The median CRP level was 4 mg/L (2, 10) among the study population. Patients with raised CRP had higher summed stress score (SSS) (p = 0.006) and summed rest score (SRS) (p = 0.001) and higher risk for SSS > 3 (OR 9.25, 95% CI 2.03-42.13, p = 0.001) compared to those with low CRP. The association of SSS and SRS with CRP levels was more evident in patients over 70 years (p = 0.027 and p = 0.005, respectively). No significant difference in summed difference score was shown. The two groups had no difference in other risk factors (p > 0.05 for all comparisons).

CONCLUSION

a high level of CRP was associated with the presence and extent of stress-induced myocardial ischemia in MPI.

Body Mass Index Is Independently Associated with the Presence of Ischemia in Myocardial Perfusion Imaging

Background and Objectives: Obesity has been linked to various cardiovascular risk factors, increased incidence of coronary artery disease, and myocardial perfusion defects. The aim of this study was to investigate if body mass index (BMI) and waist circumference (WC) were associated with myocardial perfusion defects. Materials and Methods: A total of 308 consecutive patients who had myocardial perfusion imaging (MPI) with single photon emission computed tomography (SPECT) and a complete medical record on file were studied retrospectively. Results: The median age was 69 (61−76) years, the BMI was 27.6 (24.4−30.7) kg/m2, and the WC was 110 (102−118) cm. Of the 308 patients, 239 patients (77.6%) had myocardial ischemia. A positive test for ischemia was more frequent in men compared to women (72 vs. 28%, p < 0.001). Within the male group, BMI and WC were not significantly different between the ischemia and non-ischemia groups. In contrast, within the female group, both BMI (30.2 vs. 27.1 kg/m2, p = 0.002) and WC (112 vs. 105.5 cm, p = 0.020) were significantly higher in the ischemia group. Multivariable logistic regression showed that male sex and BMI were the only two independent predictors of ischemia in our patient population. Conclusions: This study showed that BMI was an independent predictor of ischemia in our patient population.