Targeted Therapies for Microvascular Disease.

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.

Coronary perforation incidence, outcomes and temporal trends (COPIT): a systematic review and meta-analysis.

Coronary perforation is a potentially life-threatening complication of percutaneous coronary intervention (PCI). We studied incidence, outcomes and temporal trends following PCI-related coronary artery perforation (CAP). METHODS: Prospective systematic review and meta-analysis including meta-regression using MEDLINE and EMBASE to November 2020. We included 'all-comer' PCI cohorts including large PCI registries and randomised controlled trials and excluding registries or trials limited to PCI in high-risk populations such as chronic total occlusion PCI or cohorts treated only with atheroablative devices. Regression analysis and corresponding correlation coefficients were performed comparing perforation incidence, mortality rate, tamponade rate and the rate of Ellis III perforations against the midpoint (year) of data collection to determine if a significant temporal relationship was present. RESULTS: 3997 studies were screened for inclusion. 67 studies met eligibility criteria with a total of 5 568 191 PCIs included over a 38-year period (1982-2020). The overall pooled incidence of perforation was 0.39% (95% CI 0.34% to 0.45%) and remained similar throughout the study period. Around 1 in 5 coronary perforations led to tamponade (21.1%). Ellis III perforations are increasing in frequency and account for 43% of all perforations. Perforation mortality has trended lower over the years (7.5%; 95% CI 6.7% to 8.4%). Perforation risk factors derived using meta-regression were female sex, hypertension, chronic kidney disease and previous coronary bypass grafting. Coronary perforation was most frequently caused by distal wire exit (37%) followed by balloon dilation catheters (28%). Covered stents were used to treat 25% of perforations, with emergency cardiac surgery needed in 17%. CONCLUSION: Coronary perforation complicates approximately 1 in 250 PCIs. Ellis III perforations are increasing in incidence although it is unclear whether this is due to reporting bias. Despite this, the overall perforation mortality rate (7.5%) has trended lower in recent years. Limitations of our findings include bias that may be introduced through analysis of multidesign studies and registries without pre-specified standardised perforation reporting CMore research into coronary perforation management including the optimal use of covered stents seems warranted. PROSPERO REGISTRATION NUMBER: CRD42020207881.

Predictors and Prognostic Implications of Well-Matured Coronary Collateral Circulation in Patients with a Chronic Total Occlusion (CTO).

The predictors and prognostic implications of well-matured collaterals in those with a chronic total occlusion (CTO) are unknown. We sought to identify the determinants of collateral maturation and to determine its effects on procedural outcomes and prognosis.Patients presenting for CTO percutaneous coronary intervention (PCI) between April 2010 and July 2019 were included. Patients with a previous coronary artery bypass (CABG) to the CTO and those with only bridging collaterals were excluded. The degree of collateral maturation was determined by the Rentrop grading classification. Demographic, biochemical, and anatomical factors and procedural and longer-term outcomes were identified.A total of 212 patients were included in the study. Patients with well-matured collaterals were more likely to be females (29.7% versus 15.2% versus 0%, P < 0.005 for Rentrop grade 3, 2, and 0 or 1, respectively), less likely to have chronic kidney disease (CKD) (8.8% versus 4.5% versus 19.2%, P < 0.05) and less likely to have had a prior CABG (15.6% versus 18.7% versus 19.2%). Patients with well-matured collaterals had lower neutrophil-to-leukocyte ratio (NLR) (2.8 versus 4.0 versus 5.7, P < 0.0001). Patients with well-matured collaterals were more likely to have procedural success (90.5% versus 62.5% versus 34.6%, P < 0.0001). The degree of collateral maturation was not associated with longer-term mortality.Improved collateral maturation was associated with female sex and lower rates of CKD and CABG and a lower NLR. Those with well-matured collaterals had a significantly higher rate of procedural success but not improved prognosis.