Biopsy-proven lupus nephritis (LN) may be an affair of the heart as much as of the kidneys, according to a study recently published in the Journal of Rheumatology. A team of Danish investigators monitored 104 patients, all of whom had biopsy-proven LN. They compared the incidence of ischemic heart disease (IHD) in the general population of Denmark with that occurring after the first renal biopsy in the study group by calculating standardized ratios of observed to expected events (O:E ratios). Patients were monitored for an average of 14.7 years.
Thirty-one of the patients with LN experienced first-time hospitalization for IHD, for an O:E ratio of 6.8. These patients were at increased risk for angina pectoris, myocardial infarction (MI), and other IHD-related diagnoses combined (O:E ratios, 6.0, 7.9, and 6.9, respectively). Patients at greatest risk for IHD were those who were older than 31 years at the time of first biopsy and in their thirties during follow-up (O:E ratios, 17.1 and 42.3, respectively). Persons who received long-term renal replacement therapy also were at significantly higher risk for IHD than controls (O:E ratio, 19.4).
These findings suggest that patients with LN—especially those who received the diagnosis at a young age—are at very high risk for angina, MI, and other types of IHD compared with the general population.