Drivers of mortality in patients with chronic coronary disease in the low-dose colchicine 2 trial

BACKGROUND: Low-dose colchicine significantly reduces the risk of cardiovascular events in patients with chronic coronary disease. An increase of non-cardiovascular death raised concerns about its safety. This study reports cause-specific mortality and baseline predictors of mortality in the Low-Dose Colchicine 2 (LoDoCo2) trial.

METHODS: Patients with chronic coronary disease were randomly allocated to colchicine 0.5 mg once daily or placebo on a background of optimal medical therapy. Cause-specific mortality data were analysed, stratified by treatment status. Multivariate analyses were performed to examine the predictors of mortality as well as cardiovascular and non-cardiovascular death.

RESULTS: After a median 28.6 months follow-up, 133 out of 5522 participants (2.4%) died. Forty-five deaths were cardiovascular (colchicine versus placebo: 20 [0.7%] versus 25 [0.9%], HR, 0.80; 95% CI, 0.44-1.44), while eighty-eight deaths were non-cardiovascular (53 [1.9%] versus 35 [1.3%]; HR, 1.51; 95% CI, 0.99-2.31). Forty-eight deaths were due to cancer (26 [0.9%] versus 22 [0.8%]), thirteen end-stage pulmonary disease (9 [0.3%] versus 4 [0.1%]), eight infection (4 [0.1%] versus 4 [0.1%]), five dementia (4 [0.1%] versus 1 [0.0%]) and five related multiple organ failure (3 [0.1%] versus 2 [0.1%]). Multivariable analysis demonstrated age > 65 years was the only independent baseline characteristic associated with non-cardiovascular death (HR, 3.65; 95% CI, 2.06-6.47).

CONCLUSIONS: During the LoDoCo2 trial, assignment to colchicine was not associated with an adverse effect on any specific causes of death. Most deaths were related to non-cardiovascular causes, underscoring the importance of comorbidities as drivers of all-cause mortality in patients with chronic coronary disease.