Anti-mitochondrial M2 Ab (AMA-M2) in 987 IIM pts-- 55 (6%) were AMA-M2 positive. AMA-M2+ had signif. higher rates of polymyositis (56% vs 23.5%), GGT, alk phos levels, & 3 fold more cardiac involvement (60 vs 13%) (arrhythmias, CHF, pulm HTN (31-56%), but no effect on survival https://t.co/WYWeDpiYOh