Which diameter and angle rule provides optimal flow patterns in a coronary bifurcation?

The branching angle and diameter ratio in epicardial coronary artery bifurcations are two important determinants of atherogenesis. Murray's cubed diameter law and bifurcation angle have been assumed to yield optimal flows through a bifurcation. In contrast, we have recently shown a 7/3 diameter law (HK diameter model), based on minimum energy hypothesis in an entire tree structure. Here, we derive a bifurcation angle rule corresponding to the HK diameter model and critically evaluate the streamline flow through HK and Murray-type bifurcations. The bifurcations from coronary casts were found to obey the HK diameter model and angle rule much more than Murray's model. A finite element model was used to investigate flow patterns for coronary artery bifurcations of various types. The inlet velocity and pressure boundary conditions were measured by ComboWire. Y-bifurcation of Murray type decreased wall shear stress-WSS (10%-40%) and created an increased oscillatory shear index-OSI in atherosclerosis-prone regions as compared with HK-type bifurcations. The HK-type bifurcations were found to have more optimal flow patterns (i.e., higher WSS and lower OSI) than Murray-type bifurcations which have been traditionally believed to be optimized. This study has implications for changes in bifurcation angles and diameters in percutaneous coronary intervention

Primary Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction, Resuscitated Cardiac Arrest, and Cardiogenic Shock The Role of Primary Multivessel Revascularization

ObjectivesThis study sought to assess the impact of multivessel (MV) primary percutaneous coronary intervention (PCI) on clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) presenting with cardiogenic shock (CS) and resuscitated cardiac arrest (CA).BackgroundThe safety and efficacy of MV primary PCI in patients with STEMI and refractory CS is unknown.MethodsWe conducted a multicenter prospective observational study of consecutive STEMI patients presenting to 5 French centers. Patients were classified as having single-vessel (SVD) or multivessel (MVD) coronary disease, and underwent culprit-only or MV primary PCI. Baseline characteristics and 6-month survival were compared.ResultsAmong 11,530 STEMI patients, 266 had resuscitated CA and CS. Patients with SVD (36.5%) had increased 6-month survival compared to those with MVD (29.6% vs. 42.3%, p = 0.032). Baseline characteristics were similar in those with MVD undergoing culprit-only (60.9%) or MV (39.1%) primary PCI. However, 6-month survival was significantly greater in patients who underwent MV PCI (43.9% vs. 20.4%, p = 0.0017). This survival advantage was mediated by a reduction in the composite of recurrent CA and death due to shock (p = 0.024) in MV PCI patients. In those with MVD, culprit artery PCI success (hazard ratio [HR]: 0.63; 95% confidence interval [CI]: 0.41 to 0.96, p = 0.030) and MV primary PCI (HR: 0.57; 95% CI: 0.38 to 0.84, p = 0.005) were associated with increased 6-month survival.ConclusionsThe results of this study suggest that in STEMI patients with MVD presenting with CS and CA, MV primary PCI may improve clinical outcome. Randomized trials are required to verify these results

072 Five-year outcome of patients with bifurcation lesions treated with provisional side branch T-stenting using drug-eluting stents

BackgroundCoronary bifurcation lesions remain a challenge, as lower success rates and higher reintervention rates persist in this lesion subset. The ideal strategy to treat such lesions is still debated and data regarding long-term efficacy and safety of drug-eluting stents in this setting are sparse.ObjectivesWe sought to determine the long-term efficacy and safety of a provisional side branch T-stenting (PTS) strategy for bifurcation lesions in an unselected population.Methods477 consecutive Pts were treated for bifurcation lesions with DES (Paclitaxel or Sirolimus-eluting stents) between 2003 and 2005. Data were entered prospectively into a single-center registry. The PTS strategy was employed in 92%, with a side-branch stent in 28% and final kissing balloon inflation in 95%. Five-year follow-up, at a median of 61 months, is available for 93.5% of patients.ResultsAngiographic success was achieved in 99%, with 2.5% in-hospital major adverse cardiac events (MACE, defined as any cardiac death, early reintervention, Q – or non-Q-wave MI or target vessel revascularisation). The cumulative rate of MACE was 10.7% at 1 year, 13.6% at 2 years and 19.7% at 5 years, including target vessel revascularisation rates of 6.9%, 8.9% and 13%, and cardiac death rates of 3%, 3.7% and 6.7%, respectively. Ischaemia-driven target lesion revascularisation at 5 years is 7.3%. The cumulative rate of definite or probable stent thrombosis at long-term is 3.1%, most cases occurring within the first year (2.5%). The need for reintervention in the long-term was not predicted by any procedural variable, and not significantly related to the use of 1 or 2 stents or to the type of stent deployed.ConclusionsA PTS strategy with first generation drug-eluting stents, was applicable to over 90% of real-world patients with bifurcation lesions with a target lesion revascularisation < 10% at 5 years. The rate of very-late stent thrombosis in this complex lesion subset remains low

Derivation and Validation of a Chronic Total Coronary Occlusion Intervention Procedural Success Score From the 20,000-Patient EuroCTO Registry: The EuroCTO (CASTLE) Score.

OBJECTIVES: The aim was to establish a contemporary scoring system to predict the outcome of chronic total occlusion coronary angioplasty. BACKGROUND: Interventional treatment of chronic total coronary occlusions (CTOs) is a developing subspecialty. Predictors of technical success or failure have been derived from datasets of modest size. A robust scoring tool could facilitate case selection and inform decision making. METHODS: The study analyzed data from the EuroCTO registry. This prospective database was set up in 2008 and includes >20,000 cases submitted by CTO expert operators (>50 cases/year). Derivation (n = 14,882) and validation (n = 5,745) datasets were created to develop a risk score for predicting technical failure. RESULTS: There were 14,882 patients in the derivation dataset (with 2,356 [15.5%] failures) and 5,745 in the validation dataset (with 703 [12.2%] failures). A total of 20.2% of cases were done retrogradely, and dissection re-entry was performed in 9.3% of cases. We identified 6 predictors of technical failure, collectively forming the CASTLE score (Coronary artery bypass graft history, Age (≥70 years), Stump anatomy [blunt or invisible], Tortuosity degree [severe or unseen], Length of occlusion [≥20 mm], and Extent of calcification [severe]). When each parameter was assigned a value of 1, technical failure was seen to increase from 8% with a CASTLE score of 0 to 1, to 35% with a score ≥4. The area under the curve (AUC) was similar in both the derivation (AUC: 0.66) and validation (AUC: 0.68) datasets. CONCLUSIONS: The EuroCTO (CASTLE) score is derived from the largest database of CTO cases to date and offers a useful tool for predicting procedural outcome