Inflammatory Bowel Disease Linked With Coronary Microvascular Dysfunction: JAHA

A recent clinical study has shown that the coronary flow reserve, reflecting coronary microvascular function, is impaired in patients with IBD. However, no studies have investigated the mechanisms responsible for coronary microvascular dysfunction (CMD) and the effect of IBD‐directed therapy on CMD in such patients. Therefore, researchers of Japan conducted a study to investigate the presence and severity of coronary microvascular dysfunction (CMD) in inflammatory bowel disease (IBD) including Crohn disease and ulcerative colitis and to elucidate the influence of surgical resection of the diseased intestines on CMD by assessing coronary flow velocity reserve (CFVR) using transthoracic Doppler echocardiography.

In this prospective study, researchers included a total of 67 patients, among which 37 patients were in the IBD group (22 patients with Crohn disease and 15 patients with ulcerative colitis) and 30 patients in the control group. For CFVR measurement, they recorded coronary flow velocity at rest and during hyperemia by ADP infusion using transthoracic Doppler echocardiography, and CFVR <2.5 defined CMD. They repeated CFVR measurement before and within 1 year after surgery.

Key findings of the study were:

• At baseline, the researchers found that CFVR was similarly and significantly lower in patients with Crohn disease and those with ulcerative colitis than controls (Crohn disease: 2.92±1.03, ulcerative colitis: 2.99±0.65, and controls: 3.84±0.75).
• After surgery, coronary flow velocity was not significantly altered in IBD patients without CMD, whereas for those with CMD, the resting CFV was reduced (-19%±25%) and hyperemic CFV ameliorated (21%±34%).
• Upon multiple linear regression analysis, they found that the presence of IBD and baseline hs‐CRP (high‐sensitivity C‐reactive protein) were independently associated with low CFVR among all study participants (β=−0.403 and −0.237).
• They also found that the reduction of hs‐CRP was independently associated with improvement of hyperemic coronary flow velocity and CFVR among all patients with IBD (β=−0.481and β=−0.334).

The authors concluded, "IBD was associated with CMD assessed as impaired CFVR, which improved after surgery, especially in patients with CMD at baseline. The reduction of hs‐CRP was significantly and independently associated with CFVR improvement. Therefore, IBD may have specific pathophysiological mechanisms responsible for the development of CMD related to systemic inflammation."

For further information:

https://www.ahajournals.org/doi/10.1161/JAHA.120.019125