Acute Coronary Syndromes and Inflammatory Bowel Disease: The Gut–Heart Connection

(1) Background: Inflammatory bowel disease (IBD) induces a process of systemic inflammation, sharing common ground with acute coronary syndromes (ACS). Growing evidence points towards a possible association between IBD and an increased risk of ACS, yet the topic is still inconclusive. Therefore, we conducted a systematic review aiming to clarify these gaps in the evidence. (2) Methods: We conducted a systematic search on EMBASE, Cochrane Library, and PubMed, identifying observational studies published prior to November 2020. The diagnosis of IBD was confirmed via histopathology or codes. Full articles that fulfilled our criteria were included. Quality assessment was performed using the Newcastle–Ottawa scale (NOS). (3) Results: We included twenty observational studies with a total population of ~132 million subjects. Fifteen studies reported a significant association between ACS and IBD, while the remaining five studies reported no increase in ACS risk in IBD patients. (4) Conclusions: ACS risk in IBD patients is related to hospitalizations, acute active flares, periods of active disease, and complications, with a risk reduction during remission. Interestingly, a general increase in ACS risk was reported in younger IBD patients. The role of corticosteroids and oral contraceptive pills in increasing the ACS risk of IBD patients should be investigated.