Retrograde Dissection Re-entry Research Articles

Changes in coronary collateral function after successful chronic total occlusion percutaneous coronary intervention.

Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) incorporates wire escalation and dissection/re-entry recanalisation strategies. The purpose of the study was to investigate changes in collateral function after CTO PCI and to identify whether the mode of successful recanalisation influences collateral function regression. Patients scheduled for elective CTO PCI with evidence of viability in the CTO territory by noninvasive imaging were included in this study. After successful CTO PCI, the aortic pressure (Pa) and distal coronary artery wedge pressure (Pw) during balloon occlusion were measured, both in a resting state and during infusion of intravenous adenosine, allowing the calculation of the pressure-derived collateral pressure index at rest and hyperaemia (CPIrest and the collateral fractional flow reserve [FFRcoll], respectively). Measurements were repeated 3 months later during angiographic follow-up. Eighty-one patients had physiological measurements at baseline and follow-up. In the final cohort the mean age was 64 years and 82% were male. The mean maximal stent diameter and total stent length were 3.2±0.5 mm and 68±31 mm, respectively. Successful strategies were antegrade wiring (64.2%), antegrade dissection re-entry (8.6%), and retrograde dissection re-entry (27.1%). Between the index procedure and follow-up, wedge pressure decreased from 34±11 mmHg to 21±8.5 mmHg (p<0.01), respectively. FFRcoll changed from 0.34±0.11 to 0.19±0.09 (p<0.01) at follow-up and CPIrest from 0.40±0.14 to 0.17±0.09 (p<0.01). Absolute maximum collateral flow decreased from 55±32 ml/min directly after PCI to 38±24 ml/min (p<0.01). There was no relation between the recanalisation technique and changes in FFRcoll. There was a significant reduction in collateral flow over time, independent of the recanalisation technique.

The association of myocardial injury during chronic total occlusion percutaneous coronary intervention with lesion complexity and treatment strategy

Abstract Background Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with procedural myocardial injury (PMI), and adverse long-term clinical outcomes [1–4].CTO lesion complexity is quantified using established scores [5–8], with high complexity known to determine the need for dissection and re-entry techniques and the retrograde approach, which are then associated with a higher incidence of procedural complications [9,10]. If CTO recanalization is unsuccessful, a modification procedure can be performed, with the intention to improve subsequent procedural success [11–14]. There are limited data on the association between PMI, CTO complexity and treatment strategy. Purpose To report the incidence of myocardial injury following CTO PCI, and assess whether this is associated with lesion complexity, crossing strategy, or the use of a modification procedure. Methods This is a retrospective analysis of consecutive elective CTO PCI procedures performed at a single centre in Norway between January 2020 and March 2021. High-sensitivity troponin T (hsTnT) was measured pre and 12–18 hours post-procedure. Myocardial injury defined as a post-procedure elevation of hsTnT &amp;gt;5x 99th percentile URL with a normal baseline value or a rise &amp;gt;20% with elevated pre-procedure hsTnT. CTO complexity was described using the J-CTO, PROGRESS, RECHARGE and EuroCASTLE scores [5–8]. Procedures were classified as technical successful or unsuccessful according to CTO academic research consortium (CTO-ARC)criteria [15], and further categorised according to final crossing strategy [antegrade wiring (AW), antegrade dissection re-entry (ADR), retrograde wiring (RW) or retrograde dissection re-entry (RDR)]. If unsuccessful they were further categorised as “failure” or “unplanned modification procedure”. A “planned modification procedure” defined as intentional antegrade modification of the occlusive segment with no attempt to complete CTO crossing. Results We analysed 122 CTO PCI procedures. Mean J-CTO, PROGRESS, RECHARGE, EuroCASTLE scores were 2.7, 1.2, 3.0 and 3.1 respectively. Technical success during the index procedure was 75%. An unplanned or planned modification procedure was performed in 16% and 2% of cases, respectively. Technical failure occurred in 7% of cases. Myocardial injury occurred in 65% of all procedures (78% of failed procedures, 64% of successful procedures, 63% of unplanned and none of 3 planned CTO modification procedures). The mean hs-TnT according to treatment strategy and outcomes are reported in Table 1. The relationship between the CTO complexity scores and hs-TnT are illustrated in Figure 1. Conclusions Myocardial injury is common during CTO PCI, particularly with more complex anatomy, requiring the retrograde approach or an unplanned modification procedure. A prospective analysis of whether myocardial injury can be avoided using a planned investment procedure in high complexity cases is currently being conducted. Funding Acknowledgement Type of funding sources: None.

Procedure Planning: Anatomical Determinants of Strategy

In contemporary practice there are three main methods that can be employed when attempting to open a chronic total occlusion (CTO) of a coronary artery; antegrade or retrograde wire escalation, antegrade dissection re-entry and retrograde dissection re-entry. This editorial will attempt to clarify the anatomical features that can be identified to help when deciding which of these strategies to employ initially and help understand the reasons for this decision.