Evaluating heart function using an electrocardiogram (ECG) can be a useful noninvasive tool for early detection of patients with systemic lupus erythematosus (SLE) who have an increased risk for cardiovascular disease (CVD), researchers found.
The study, “Prevalence and associated factors of resting electrocardiogram abnormalities among systemic lupus erythematosus patients without cardiovascular disease,” was published in the journal Arthritis Research & Therapy.
SLE is considered an independent risk factor for heart disease, and is incorporated in the American Heart Association guidelines for prevention of cardiovascular disease in women. Despite increasing awareness and preventive clinical practices, 6-10 percent of patients with SLE have coronary artery disease.
To determine the prevalence of electrocardiogram cardiovascular disease abnormalities (ECG-CVD) in SLE patients and possible associated risk factors, researchers evaluated the ECG profiles of 558 patients admitted to the University of Toronto SLE Clinic, from October 2011 to November 2015.
The identification of ECG-CVD was based on the presence of abnormalities in different elements of an ECG that are recognized as risk factors for heart problems: ST-segment and/or T-wave abnormalities; left ventricular hypertrophy (LVH); left axis deviation (LAD); left bundle branch block (LBBB); right bundle branch block (RBBB); and abnormal Q wave.
Of all patients enrolled in the study, 314 patients had a normal ECG, 118 patients showed ECG-CVD, and 55 patients presented ECG abnormalities that were not associated with CVD. Any patient who suffered a CVD event prior to ECG, such as angina, congestive heart failure, angioplasty or pacemaker were excluded from the study.
The researchers found the most common abnormality was in the ST-segment and/or T-wave (related to the heart’s activity), with a frequency of 70%. The majority of the SLE patients with ECG-CVD presented only one abnormal element, while 25% showed two abnormal elements, and 7% had three ECG-CVD elements.
ECG-CVD elements were found to be more prevalent in older patients with an average age of 50, compared to the group of lupus patients without ECG-CVD, who were approximately 45 years old. Indeed, older patients were found to have an increased risk for CVD of 4% for every one-year increase in age.
Patients with ECG-CVD elements had a more active SLE disease as measured by the SLE Disease Activity Index 2000 two years prior to the ECG visit, and also had more damage, as measured by the SLICC/American College of Rheumatology Damage Index, compared to patients with a normal ECG. Also, ECG-CVD was more common in patients who had lupus for a longer period of time.
The authors concluded that an early identification of ECG-CVD elements in SLE patients might allow for better stratification and risk management.
The high prevalence of ECG-CVD elements found in this study suggested that lupus patients without documented cardiovascular disease are at risk for heart problems. The team believes that ECG can be an important tool for prevention of cardiovascular events in lupus patients.
However, the authors emphasized the importance of validating targeted cardiovascular prevention strategies in patients with ECG-CVD.