Risk of cardiovascular events in patients having had acute calcium pyrophosphate crystal arthritis

Abstract

ObjectivesCalcium pyrophosphate deposition (CPPD) disease, broadly defined, has been associated with increased risk of cardiovascular (CV) events. We investigated risk of CV events in patients with acute CPP crystal arthritis, the acute manifestation of CPPD.MethodsCohort study using Mass General Brigham electronic health record (EHR) data, 1991–2017. Patients with acute CPP crystal arthritis were identified using a published machine learning algorithm with positive predictive value 81%. Comparators were matched on year of EHR entry and index date of patients with acute CPP crystal arthritis (first positive synovial fluid CPP result or mention of ‘pseudogout’, or matched encounter). Major adverse cardiovascular event (MACE) was a composite of non-fatal CV event (myocardial infarction, acute coronary syndrome, coronary revascularisation, stroke) and death. We estimated incidence rates (IRs) and adjusted hazard ratios for MACE, non-fatal CV event and death, allowing for differential estimates during years 0–2 and 2–10. Sensitivity analyses included: (1) patients with acute CPP crystal arthritis diagnosed during outpatient visits, (2) patients with linked Medicare data, 2007–2016 and (3)patients matched on number of CV risk factors.ResultsWe matched 1200 acute CPP crystal arthritis patients to 3810 comparators. IR for MACE in years 0–2 was 91/1000 person-years (p-y) in acute CPP crystal arthritis and 59/1000 p-y in comparators. In years 2–10, IR for MACE was 58/1000 p-y in acute CPP crystal arthritis and 53/1000 p-y in comparators. Acute CPP crystal arthritis was significantly associated with increased risk for MACE in years 0–2 (HR 1.32, 95% CI 1.01 to 1.73) and non-fatal CV event in years 0–2 (HR 1.92, 95% CI 1.12 to 3.28) and years 2–10 (HR 2.18, 95% CI 1.27 to 3.75), but not death. Results of sensitivity analyses were similar to the primary analysis; in the outpatient-only analysis, risk of non-fatal CVE was significantly elevated in years 2–10 but not in years 0–2.ConclusionsAcute CPP crystal arthritis was significantly associated with elevated short and long-term risk for non-fatal CV event.