1Herzzentrum Dresden GmbH an der TU Dresden Klinik für Innere Medizin, Kardiologie und Intensivmedizin Dresden, Deutschland
Background: Chronic total occlusion (CTO) is frequently found in patients undergoing high-risk percutaneous coronary interventions (HRPCI). Mechanical circulatory support is increasingly used in HRPCI to facilitate a more complete revascularization. We investigated the impact of CTO presence (CTO) versus non-presence (nonCTO) on early and mid-term outcomes in patients undergoing Impella-supported HRPCI.
Methods: We used an ongoing single-center registry to examine 76 CTO and 109 nonCTO patients undergoing Impella-supported HRPCI. The primary outcome was 30-day survival and safety was assessed according to ARC-2 and VARC-III definitions. The 1-year survival was also assessed.
Results: Compared with nonCTO, CTO patients were younger (76 (IQR 67; 81) vs 81 (IQR 77; 85) years of age, p<0.001) and median left ventricular ejection fraction was lower (35% (IQR 25; 45) vs 40% (IQR 30; 55), p=0.008). There were no differences with regard ischemic (CCS 3/4: 28.8% vs 37.1%) and heart failure symptoms (NYHA III/IV: 64.0% vs 56.9%). There was a significantly higher rate of 3-vessel but a numerically lower rate of left main disease in CTO compared with non-CTO leading to a comparable median Syntax score (33 (IQR 28; 37) vs 34 (IQR 26; 44), p=0.328).
In CTO, 21 (27.6%) CTO lesions were successfully treated, 8 (10.5%) were unsuccessfully treated, and 47 (61.8%) were left untreated. Overall, fewer lesions were treated in CTO compared with nonCTO (2 (IQR 1;3) vs 3 (IQR 2; 3), p=0.001). The time of Impella support was not different between groups.
With regard to safety, there was a higher rate of myocardial infarction in CTO vs nonCTO (4.1% vs 0%, p=0.067), whereas BARC-defined bleeding and VARC-defined stroke, acute kidney injury, and access site complications were not different.
The Kaplan-Meier estimated 30-day survival was lower for CTO compared with nonCTO (63.3% (95%-CI 50.5; 79.4) vs. 88.5 (95%-CI 80.8; 96.9), p=0.002). Adjusting for the STS score, 3-vessel and left main disease, CTO remained an independent predictor of 30-day mortality (HR 2.8, 95%-CI 1.2; 6.5, p=0.016). The CTO treatment choice had no impact on 30-day mortality in this small cohort. Survival remained lower in CTO compared with nonCTO at 1 year (43.0% (95%-CI 29.2; 63.4) vs. 69.0 (95%-CI 56.1; 84.9), p=0.005).
Conclusion: In patients undergoing Impella-supported HRPCI, the presence of a CTO identifies a population at high risk for increased early and midterm mortality. Further studies are necessary to elucidate the effect of CTO revascularization on early and late outcomes in those patients.