Optimal Percutaneous Treatment Approach to Unprotected Ostial Left Anterior Descending Artery Disease: A Meta-Analysis and Systematic Review.

BACKGROUND: The optimal management strategy for significant unprotected ostial left anterior descending artery (LAD) disease remains undefined. Merits of the two most common percutaneous approaches are considered in this quantitative synthesis. METHOD: A meta-analysis was performed to compare ostial stenting (OS) and crossover stenting (CS) in the treatment of unprotected ostial LAD stenosis. The primary outcome is the disparity in target lesion revascularisation (TLR). The Mantel-Haenszel method was employed with random effect model, chosen a priori to account for heterogeneity among the included studies. RESULTS: Seven studies comprising 1,181 patients were included in the analyses. Of these, 482 (40.8%) patients underwent CS. Overall, there was a statistically significant trend in favour of CS (odds ratio 0.51, 95% confidence interval 0.30-0.86, p=0.01) with respect to the rate of TLR at follow-up. This remained true when TLR involving the left circumflex artery (LCx) was considered, even when there was a greater need for unintended intervention to the LCx during the index procedure (odds ratio 6.68, 95% confidence interval: 1.69-26.49, p=0.007). Final kissing balloon inflation may reduce the need for acute LCx intervention. Imaging guidance appeared to improve clinical outcomes irrespective of approach chosen. CONCLUSIONS: In the percutaneous management of unprotected ostial LAD disease, CS into the left main coronary artery (LMCA) appeared to reduce future TLR. Integration of intracoronary imaging was pivotal to procedural success. The higher incidence of unintended LCx intervention in the CS arm may be mitigated by routine final kissing balloon inflation, although the long-term implication of this remains unclear. In the absence of randomised trials, clinicians' discretion remains critical.

Fractional Flow Reserve and Instantaneous Wave-Free Ratio Predict Pathological Wall Shear Stress in Coronary Arteries: Implications for Understanding the Pathophysiological Impact of Functionally Significant Coronary Stenoses.

Background The pathophysiological mechanism behind adverse outcomes associated with ischemia-inducing epicardial coronary stenoses and microcirculatory dysfunction remains unclear. Wall shear stress (WSS) plays an important role in atherosclerotic plaque progression and vulnerability. We aimed to evaluate the relationship between WSS, functionally significant epicardial coronary stenoses, and microcirculatory dysfunction. Methods and Results Patients undergoing invasive coronary physiology testing were included. Fractional flow reserve, instantaneous wave-free ratio, and the index of microcirculatory resistance were measured. Quantitative coronary angiography was used to obtain the lesion percentage diameter stenosis. Computational fluid dynamics analysis was performed to calculate WSS parameters. Multiple regression analysis was performed to calculate the standardized regression coefficient (ß) for the coronary physiology indices. A total of 107 vessels from 88 patients were included. Fractional flow reserve independently predicted the total area of low WSS (ß=-0.44; 95% CI, -0.62 to -0.25; P<0.001) and maximum lesion WSS (ß=-0.53; 95% CI, -0.70 to -0.36; P<0.001) after adjusting for percentage diameter stenosis and index of microcirculatory resistance. Similarly, instantaneous wave-free ratio also independently predicted the total area of low WSS (ß=-0.45; 95% CI, -0.62 to -0.28; P<0.001) and maximum lesion WSS (ß=-0.58; 95% CI, -0.73 to -0.43; P<0.001). The index of microcirculatory resistance did not predict either low or high WSS. Conclusions Fractional flow reserve and instantaneous wave-free ratio independently predicted the total burden of low WSS and maximum lesion WSS in coronary arteries. No relationship was found between microcirculatory dysfunction and WSS.

A real-world comparison of outcomes between fractional flow reserve-guided versus angiography-guided percutaneous coronary intervention.

BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) has been shown to be superior to angiography-guided PCI in randomized controlled studies. However, real-world data on the use and outcomes of FFR-guided PCI remain limited. Thus, we investigated the outcomes of patients undergoing FFR-guided PCI compared to angiography-guided PCI in a large, state-wide unselected cohort. METHODS AND RESULTS: All patients undergoing PCI between June 2017 and June 2018 in New South Wales, Australia, were included. The cohort was stratified into the FFR-guided group when concomitant FFR was performed, and the angiography-guided group when no FFR was performed. The primary outcome was a combined endpoint of death or myocardial infarction (MI). Secondary outcomes included all-cause death, cardiovascular (CVS) death, and MI. The cohort comprised 10,304 patients, of which 542 (5%) underwent FFR-guided PCI. During a mean follow-up of 12±4 months, the FFR-guided PCI group had reduced occurrence of the primary outcome (hazard ratio [HR] 0.34, 95% confidence intervals [CI] 0.20-0.56, P<0.001), all-cause death (HR 0.18, 95% CI 0.07-0.47, P = 0.001), CVS death (HR 0.21, 95% CI 0.07-0.66, P = 0.01), and MI (HR 0.46, 95% CI 0.25-0.84, P = 0.01) compared to the angiography-guided PCI group. Multivariable Cox regression analysis showed FFR-guidance to be an independent predictor of the primary outcome (HR 0.45, 95% CI 0.27-0.75, P = 0.002), all-cause death (HR 0.22, 95% CI 0.08-0.59, P = 0.003), and CVS death (HR 0.27, 95% CI 0.09-0.83, P = 0.02). CONCLUSIONS: In this real-world study of patients undergoing PCI, FFR-guidance was associated with lower rates of the primary outcome of death or MI, as well as the secondary outcomes of all-cause death and CVS death.

The role of intracoronary thrombolysis in selected patients presenting with ST-elevation myocardial infarction: a case series.

BACKGROUND: Primary percutaneous coronary intervention (PCI) is the cornerstone of management for ST-elevation myocardial infarction (STEMI). However, large intracoronary thrombus burden complicates up to 70% of STEMI cases. Adjunct therapies described to address intracoronary thrombus include manual and mechanical thrombectomy, use of distal protection device and intracoronary anti-thrombotic therapies. CASE SUMMARY: This series demonstrates the use of intracoronary thrombolysis in the setting of large coronary thrombus, bifurcation lesions with vessel size mismatch, diffuse thrombosis without underlying plaque rupture, and improving coronary flow to allow vessel wiring and proceeding to definitive revascularization. DISCUSSION: Larger intracoronary thrombus burden correlates with greater infarct size, distal embolization, and the associated no-reflow phenomena, and propagates stent thrombosis, with subsequent increase in mortality and major adverse cardiac events. Intracoronary thrombolysis may provide useful adjunct therapy in highly selected STEMI cases to reduce intracoronary thrombus and facilitate revascularization.