Post-MI Outcomes Worse in RA

Patients with rheumatoid arthritis (RA) were at risk for long-term poor outcomes after myocardial infarction (MI), Finnish researchers found.

The cumulative all-cause mortality during 14 years of follow-up after MI among RA patients was 80.4% compared with 72.3% among matched controls, for a hazard ratio of 1.25 (95% CI 1.16-1.35, P<0.0001), according to Antti Palomäki, MD, PhD, of Turku University Hospital in Turku, Finland, and colleagues.

Factors that were associated with increased mortality among RA patients were duration of RA (HR 1.06, 95% CI 1.04-1.09, P<0.0001) per 5-year increment, use of corticosteroids (HR 1.27, 95% CI 1.11-1.45, P=0.001), and corticosteroid dosage per 1 mg/day (HR 1.05, 95% CI 1.02-1.08, P=0.002), they reported online in Rheumatology.

The leading cause of death among RA patients is cardiovascular disease, and the risk for MI has been estimated to be 1.7-fold higher than for the general population.

Previous efforts to determine post-MI outcomes in RA have been limited by short duration of follow-up and a lack of information about subsequent cardiovascular events and the potential protective or harmful effects of medication.

To provide a fuller picture of the long-term outlook for RA patients after an initial MI, Palomäki and colleagues analyzed data from the Care Register for Healthcare in Finland for the years 2005 to 2014, identifying 60,446 patients with MI, of whom 1,614 also had RA. A total of 8,070 controls were chosen as propensity score-matched controls.

In the entire cohort, median age was 73, and 62.1% were men. Patients with RA more often were women, older, and had more comorbidities. Most were seropositive.

Median duration of hospital stay after MI was 7 days for RA patients and 6 days for controls (P<0.0001). The median duration of RA before the initial MI was 14.4 years.

During the 6 months prior to MI, 45.8% of RA patients were receiving corticosteroids, 34.3% were on methotrexate, and 3% were taking biologics. Among patients who had used corticosteroids in the previous year, the median dosage was 4.1 mg/day.

Following discharge for the MI, fewer patients with RA were treated with statins (73.1% vs 77.3%, OR 0.79, 95% CI 0.69-0.91, P=0.001). “Secondary prevention with statins was less frequent in patients with RA, and given the survival disadvantage, secondary prevention in RA warrants particular attention,” the researchers noted.

Outcomes other than mortality that were analyzed included new MI, stroke, and revascularization.

Recurrent MI occurred in 2,412 patients, with 437 being in the RA group. At 1, 5, 10, and 14 years, the cumulative rates of new MI in the RA patients were 17.3%, 29.4%, 42.5%, and 46.6%, respectively, while the corresponding numbers among matched controls were 14%, 25.9%, 35.1%, and 40.9%. The HR for new MI was 1.22 (95% CI 1.09-1.36, P=0.001).

Factors that were associated with a recurrent MI were RA duration (HR 1.05, 95% CI 1.01-1.09, P=0.018) and use of corticosteroids (HR 1.25, 95% CI 1.02-1.53, P=0.029).

Strokes occurred in 1,066 patients following the initial MI, with 174 being among RA patients. Cumulative rates in the RA group at 1, 5, and 10 years were 4.6%, 13.4%, and 20.3%, while the corresponding numbers among controls were 3.8%, 12%, and 19.6%. By the end of follow-up, cumulative stroke incidence was 27% in the RA group and 25.9% in the control group, which was a nonsignificant difference (HR 1.09, 95% CI 0.92-1.31, P=0.322).

Rates of fatal stroke also did not differ significantly, at 6.4% in the RA group and 7.7% in the control group (P=0.437).

The corticosteroid dosage was significantly associated with stroke risk (HR 1.07, 95% CI 1.01-1.15, P=0.044), whereas methotrexate use was associated with a decreased risk (HR 0.65, 95% CI 0.45-0.92, P=0.016). “Methotrexate is the anchor drug of RA treatment, and our results support the role of methotrexate also among RA patients with previous MI,” the researchers observed.

A total of 1,249 patients underwent coronary artery revascularization, with 235 being in the RA group; the cumulative rate after first MI was 29.7% in the RA group and 22.9% among controls (HR 1.27, 95% CI 1.09-1.49, P=0.002). For percutaneous coronary intervention, the rates were 26.8% versus 19.2% (P<0.0001), and for coronary artery bypass surgery, the rates were 4.6% and 4.8% (P=0.427).

No factors, including duration of RA, medication use, or seropositivity, showed an association for revascularization after the initial MI.

“Patients with RA who suffer a myocardial infarction could benefit from a comprehensive evaluation and optimization of treatment to improve long-term outcomes,” the authors concluded.

A limitation of the study was the lack of data on RA disease activity or patients’ BMI.