A recent study entitled “Electrocardiographic Findings in Systemic Lupus Erythematosus: Data From an International Inception Cohort” revealed that systemic lupus erythematosus (SLE) patients also suffer from cardiac anomalies.
In the study, published in the journal Arthritis Care & Research, electrocardiographic methods were applied to verify the occurrence of cardiac abnormalities in SLE patients. SLE is a systemic autoimmune disease characterized by the fact that the body’s own immune system overreacts and attacks healthy joints and organs of the individual. Anti-Ro/SSA autoantibodies are associated with several autoimmune diseases including SLE. Serological tests for such antibodies can be useful in diagnosing the disease.
Electrocardiography (EKG) is a universally available and non-invasive tool that can be advantageous in detecting potential SLE-associated cardiovascular irregularities such as disturbances in the cardiac rhythm and anomalies in cardiac repolarization. The latter one is linked to an increased risk for ventricular arrhythmias and sudden death.
The Systemic Lupus International Collaborating Clinics (SLICC) Inception Registry is a study that involved 19 centers in eight different countries, where patients were follow-up every year for more than 9 years – October 1999 to December 2008. 779 SLE patients who have participated on the SLICC study were assessed, with the mean age of the group being 35.2 years. Laboratory tests and data on demographics, patients’ general health, medication, disease activity (Systemic Lupus Erythematosus Disease Activity Index 2000 [SLEDAI-2K]) and disease damage (SLICC/American College of Rheumatology Damage Index [SDI]) was collected and analyzed.
Besides evaluating several clinical and laboratory variables, researchers also studied the prevalence of EKG abnormalities in SLE patients. Anti-Ro/SSA autoantibodies were detected in 47.3% of the SLE patients and EKG anomalies were found to be frequent, namely nonspecific ST-T segment and left ventricular hypertrophy. A high incidence of repolarization anomalies was also found, with 15.3% of the patients having an increased heart rate corrected QT (QTc) of 440 msec or higher. The total SDI, referring to disease damage, was found to be significantly linked with a QTc higher than 440 msec. It was also found that women SLE patients between 25 and 44 years had a higher mean prevalence of most of the EKG anomalies analyzed in comparison with healthy women. Severe EKG anomalies were however rare.
The researchers concluded that a considerable number of SLE patients suffer from repolarization abnormalities. Unfortunately, a link between anti-RO/SSA autoantibodies and EKG repolarization abnormalities was not established.