https://doi.org/10.1007/s00392-025-02625-4
1Universitätsmedizin der Johannes Gutenberg-Universität Mainz Kardiologie 1, Zentrum für Kardiologie Mainz, Deutschland; 2Universitätsmedizin der Johannes Gutenberg-Universität Mainz Zentrum für Kardiologie Mainz, Deutschland
coronary microvascular dysfunction and chronic total occlusion (CTO) are much discussed topics in interventional cardiology. CTO of coronary arteries are diagnosed in about 15-25% of patients with coronary artery disease undergoing coronary angiography. Percutaneous recanalization remains a complex procedure with a lower technical success rate and higher restenosis rate compared to standard interventions. Coronary microvascular dysfunction (CMD) is a multifactorial, pathophysiological process resulting in impaired cardiac microcirculation. The impact of CMD in patients with a chronic total occlusion of a coronary artery (CTO) is unclear. Data on the occurrence and predictive value of CMD in patients with CTO is lacking. CMD can be assessed by invasive and non-invasive modalities, among which the index of microcirculatory resistance (IMR) is one of the most commonly used parameters. The aim of this study was to investigate CMD in patients with CTO and the effect of successful recanalization on microvascular function. Further, we investigate whether microvascular dysfunction can be identified as a risk factor for restenosis after CTO recanalization.
Methods and results:
Our analysis included 100 patients who had undergone successful CTO recanalization at the University Medical Center of Mainz. 65 patients showed good result in surveillance coronary angiography and 35 patients had restenosis at 6 month follow-up.
IMR measurement was performed directly after successful CTO PCI and at 6 months follow-up (Medis Suite 2.1.12.2, Medis Medical Imaging System, Leiden, the Netherlands). 57% were male with a median age of 62.5 years (42-85). The mean follow-up period was 187±14.18 days. Median J-CTO Score was 2 (1-3), CTO was localized at the RCA in 64%, at the LAD in 17% and at the RCX in 19% of the patients. All included patients had a good immediate result after CTO recanalization confirmed by Quantitative flow ratio (QFR) 0.99 (0.90-1.00). IMR values immediately after CTO recanalization were high and showed a significant decrease at 6 months follow-up (33.13 7.61 vs. 29.38± 5.59¸ p= < 0.001, normal <25). We found no difference of the IMR value between patients without restenosis and patients with restenosis at follow-up (33,81± 7.39 vs. 30.95± 8.48, p= 0.23)
Conclusions:
76% of the patients with CTO have microvascular dysfunction in the target territory after successful recanalization. At 6 months follow-up, IMR values improve but remain higer than normal. Higher IMR was not identified as a risk factor for restenosis at follow-up.