Abnormal myocardial perfusion correlates with impaired systolic strain and diastolic strain rate in systemic lupus erythematosus: a cardiovascular magnetic resonance study

Background

Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder that commonly affects the heart, resulting in a 7 to 9 times greater incidence of cardiovascular disease (CVD) in SLE patients compared to healthy controls. Female patients with SLE between 35 and 44 years old have an incidence of myocardial infarction over 50 times greater than that observed in the Framingham cohort. The clinical utility of cardiovascular magnetic resonance (CMR) first-pass perfusion for assessment of myocardial ischaemia is well-established. We hypothesised that CMR including stress first-pass perfusion would be able to detect coronary microvascular disease and subtle functional abnormalities in SLE and aimed to detect myocardial ischaemia in SLE using adenosine stress perfusion CMR.

Methods

29 SLE patients (28 female, mean age 42 ± 9 years) and 29 matched controls (28 female, mean age 42 ± 9 years) without previously known cardiovascular disease underwent CMR at 1.5T including cine, tagging, T1 mapping, T2-weighted, perfusion imaging, late gadolinium enhancement (0.15mmol/kg gadoteric acid - Dotarem®) and ECV quantification. Comorbid status, disease activity index and duration of disease were recorded for each subject.

Results

SLE patients were matched with controls for age, sex and comorbidity (Table 1). Myocardial perfusion reserve index (MPRI) was lower in SLE compared to controls (1.4 ± 0.2 vs. 1.9 ± 0.4, p<0.001), shown in Table 2. A third of lupus patients had visual evidence of non-segmental subendocardial perfusion defects, in keeping with microvascular dysfunction. No segmental perfusion defects were observed to suggest presence of epicardial coronary artery disease. There was no significant difference in LV size, mass and ejection fraction between SLE patients and controls. Peak systolic circumferential strain (-17.2 ± 1.7 vs. -19.4 ± 1.2, p<0.001) and peak diastolic strain rate (78 ± 24 vs. 118 ± 15 s^-1, p<0.001) were impaired in SLE patients. In SLE, MPRI showed a significant correlation with peak systolic strain (R= -0.76, p<0.001) and peak diastolic strain rate (R= 0.65, p<0.001), depicted in Figure 1.

Table 1 Baseline characteristics of SLE patients and controls

Table 2 Myocardial structure, function and perfusion in SLE patients and controls

Conclusions

Myocardial perfusion is impaired in patients with SLE with no known heart disease. In these patients, impaired MPRI was associated with abnormal myocardial deformation characteristics. It is likely that chronic disease activity and myocardial inflammation results in abnormalities in microvascular function which predate the development of myocardial functional derangements. CMR is an important tool for assessment of subclinical myocardial disease in SLE.

Funding

This study was funded by investigator-led grants from Guerbet and GlaxoSmithKline.