Background: Rheumatoid arthritis (RA) is regarded as a high risk factor for myocardial infarction. Hypertension is a major modifiable risk factor contributing to increased risk of myocardial infarction (MI). Dual blood pressure (BP)-lowering and anti-inflammatory effect of renin-angiotensin-system (RAS) inhibitors may possess protective effect from MI in RA population. However, treatment of hypertension with RAS inhibitors and MI in RA population remains unclear.
Methods: We investigated whether RAS blockade could decrease risk of incident MI in hypertensive patients with RA. We identified patients with RA and hypertension from the Registry for Catastrophic Illness, a nation-wide database encompassing almost all of the RA patients in Taiwan from 1995 to 2008. The primary endpoint was MI and the median duration of follow up was 2,986 days. Propensity score weighting and Cox proportional hazards regression models were used to estimate hazard ratios for MI.
Results: Among 27,335 subjects, 9.9% received angiotensin-converting enzyme inhibitors (ACEIs), 25.9% received angiotensin II receptor blockers (ARBs) and 20.0% received ACEIs or ARBs alternatively. The incidence of MI significantly decreased in patients treated with ACEIs (hazard ratio 0.707; 95% confidence interval 0.595-0.840), ARBs (0.641; 0.550-0.747) and ACEIs/ARBs (0.631; 0.539-0.739). The protective effect of ACEI or ARB therapy was significantly better in patients taking longer duration. The effect remained robust in subgroup analyses.
Conclusions: Therapy of ACEIs or ARBs is associated with a lower risk of MI among patients with RA. Hence, hypertension in patients with RA could comprise a compelling indication for RAS inhibitors.