Objectives: Chronic total occlusions (CTOs) of coronary arteries are diagnosed in 16-20% of patients undergoing coronary angiography. Big register studies demonstrated that the CTO is localized in the RCA in 60% of the patients. The benefit of CTO PCI is still controversial.  With our study we aimed to study the impact of RCA CTO PCI on right and left ventricular function, clinical symptoms and investigate possible influencing factors (e.g. coronary collateral circulation and anatomy of the dominant right ventricular function). 

Methods: Our analysis included 102 patients undergoing successful RCA CTO recanalization at the University Medical Center of Mainz. All patients underwent two-dimensional transthoracic echocardiography (2DE) and two-dimensional speckle-tracking echocardiography (2DSTE) to assess RV function before PCI procedure and 6 months after successful revascularization. Correlation of coronary collateral circulation was assessed by Rentrop und Werner classification.

Results: In our collective 65 of the enrolled patients reported an improvement in CCS class (63.7% and p < 0.001) and 51 an improvement in NYHA class (51.0% and p < 0.001). Complete freedom of angina was achieved in 72.5% of the patients in our collective and 58.8% of the patients reported to having no limitation of physical activity in daily life (NYHA stage 1) at follow-up. We found an altered RV function in our collective at baseline assessed by 2DSTE with a significant improvement at 6 months follow-up (baseline RV free wall strain: -20.7 [-6.3 to-32.0] % vs. -23.4 [-8.3 to-39.3] % at follow-up, p < 0.001 and baseline RV global strain -15.9 [-6.0 to-25.7] % vs. -17.9 [-7.0 to -29.5] % at follow-up, p < 0.001). We found no impact of Werners’ classification or Rentrop classification on the right ventricular function. The location of the CTO (proximal vs. distal to the dominant right ventricular side branch also had no effect on RV function. After patients were divided into the following groups: RVSB occluded before and after PCI, RVSB not occluded before and after PCI, RVSB occluded before and not occluded after PCI and RVSB not occluded before and occluded after PCI). We found no difference between the groups, the patients benefited regardless of side branch anatomy. 

Conclusion: RV function was altered in patients with RCA CTO and showed significant improvement after successful recanalization. This effect was independent of coronary collateral circulation and the anatomy of the RV branch. We also noticed an improvement in patients-reported clinical symptoms. Our study suggests that CTO procedure is a beneficial treatment option in symptomatic patients with RCA CTO.