Complications of myocarditis in inflammatory bowel disease (ibd): a population-based comparative study between ulcerative colitis and crohn's disease

Abstract INTRODUCTION Cardiac Complications are common in IBD. Myocarditis is a serious extraintestinal manifestation associated with inflammatory bowel disease. The aim of this study is to investigate the complications associated with myocarditis in patients who have IBD (Ulcerative Colitis vs Crohn’s Disease) patients. METHODS Methods Data was extracted from the National Inpatient Sample (NIS) 2016-2019 Database. The NIS was searched for hospitalizations for adult patients with myocarditis as a principal discharge diagnosis who had Ulcerative Colitis (UC) versus those with Crohn’s Disease (CD) as secondary diagnosis using ICD-10 codes. The primary outcome was inpatient mortality. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. STATA software was used for analysis. Characteristics and complications of myocarditis were compared between UC and CD. RESULTS A total of 874,285 hospitalized patients aged ≥18 years had IBD, of which 563,700 (64.48%) had UC and 310,585 (35.52%) had CD. Myocarditis was present in 250 (0.03%) patients; 100 UC (0.34%) and 150 CD (0.52%). Overall prevalence of myocarditis was 18.87 per 100,000 hospitalizations for IBD patients. Prevalence was 23.22 in UC (Mean age 48.5 ± 2.1 years p<0.001, 56% women p<0.001, 76% Caucasian p<0.001) and 11.55 in CD (Mean age 39.5± 1.42 years, p<0.001; 37% women, p<0.001; 72% Caucasian, p <0.001) per 100,000 hospitalizations respectively (p<0.001). Annual incidence of myocarditis was rising for UC over a 5-year period per 100,000 hospitalizations (13.6 in 2016, 25.1 in 2019, ptrend = 0.04) and for CD (10.3 in 2016, 13.4 in 2019, ptrend = 0.03). In patients with myocarditis, UC patients had lesser in-hospital mortality (3.4% % vs. 5.2 %, p< 0.001), AKI (5.3% vs. 13.4%, p< 0.001), congestive heart failure (14.5% vs. 33.2%, p<0.001) and cardiogenic shock (4.3% vs. 8.7%, p<0.001) compared to CD. Atrial fibrillation was the most common arrhythmia in both UC and CD (6.1% vs. 6.2%, p = 0.968). Ventricular fibrillation was higher in CD (3.4% vs. 1.1%, p<0.001). CONCLUSION Interestingly, Myocarditis was associated with higher mortality, higher cardiac complications and was more prevalent in patients with CD compared to UC. Further randomized controlled trials are necessary to determine the mechanisms between IBD and cardiovascular diseases and to study the disparity between UC and CD. This study further illustrates the importance of successful management of IBD in order to reduce disease activity and cardiovascular risk factors.