Coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve replacement (TAVR). While urgent percutaneous coronary intervention has been described in cases ...of acute occlusion, little is known about the interventional management of obstruction once it has occurred in the chronic setting. We describe a case in which electrocautery-assisted re-entry was successfully utilized to manage the right coronary artery and left main chronic total occlusion due to leaflet-induced coronary artery obstruction after TAVR.
Cardiac allograft vasculopathy (CAV) is frequently observed after heart transplant (HT), and represents one of the main causes of chronic rejection, graft loss, and death. While the role of ...percutaneous coronary intervention (PCI) is well established in the management of CAV in cases of nonocclusive stenoses, the outcomes and technical aspects of this procedure in chronic total occlusions (CTOs) are unknown. We describe our experience with three cases in which CTO PCI was indicated to treat CAV in HT recipients, and we discuss the peculiarities and therapeutic approach to this challenging patient population. In particular, all patients were asymptomatic for angina, and CTO PCI was indicated to promote recovery of left ventricular function, extend graft survival, and/or protect from future ischemic events. CTO PCI was performed using hybrid techniques and was successful in all three cases. Intravascular imaging was used in all cases to maximize the durability of the procedure.
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Chronic total occlusions (CTOs) are an important and increasingly recognized subgroup of coronary lesions, documented in at least 30%, but up to 52% of patients with coronary artery disease (CAD) ...undergoing coronary angiography. Percutaneous coronary intervention (PCI) of these lesions is increasingly pursued, with excellent success rates.
Purpose of Review
It is known that gender differences exist in the presentation of CAD, as well as in clinical outcomes after routine PCI; however, it is not well described how these differences pertain to management of CTOs. This review summarizes the available data regarding sex-based differences in CTO management and outcomes.
Recent Findings
Women comprise approximately 20% of CTO registry and trial participants.
Summary
As has been demonstrated in PCI studies, women comprise a minority of patients in CTO PCI registries and trials. Sex-based differences exist in complication rates, collateral formation, and outcomes and need further evaluation in future studies.
Velocity of capillary flow in closed or open channels decreases as the flow proceeds down the length of the channel, varying as the inverse of the square root of time or as the inverse of travel ...distance. In order to increase the flow rateand extend the duration of the flowcapillary pumps have been designed by mimicking the pumping principle of paper or cotton fibers. These designs provide a larger volume available for the wicking of the liquids. In microsystems for biotechnology, different designs have been developed based on experimental observation. In the present paper, the mechanisms at the basis of capillary pumping are investigated using a theoretical model for the flow in an open-channel “capillary tree” (i.e., an ensemble of channels with bifurcations mimicking the shape of a tree). The model is checked against experiments. Rules for obtaining better designs of capillary pumps are proposed; specifically, we find (1) when using a capillary tree with identical channel cross-sectional areas throughout, it is possible to maintain nearly constant flow rates throughout the channel network, (2) flow rate can be increased at each branch point of a capillary tree by slightly decreasing the areas of the channel cross section and decreasing the channel lengths at each level of ramification within the tree, and (3) higher order branching (trifurcations vs bifurcations) amplify the flow rate effect. This work lays the foundation for increasing the flow rate in open microfluidic channels driven by capillary flow; we expect this to have broad impact across open microfluidics for biological and chemical applications such as cell culture, sample preparation, separations, and on-chip reactions.
Background
Risk stratification before chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is important to inform procedural planning as well as patients and their families. We ...sought to externally validate the PROGRESS‐CTO complication risk scores in the OPEN‐CTO registry.
Methods
OPEN‐CTO is a prospective registry of 1000 consecutive CTO PCIs performed at 12 experienced US centers using the hybrid algorithm. Endpoints of interest were in‐hospital all‐cause mortality, need for pericardiocentesis, acute myocardial infarction (MI), and major adverse cardiovascular events (MACE) (a composite of all‐cause mortality, stroke, periprocedural MI, urgent repeat revascularization, and tamponade requiring pericardiocentesis). Model discrimination was assessed with the area under the curve (AUC) method, and calibration with the observed‐versus‐predicted probability method.
Results
Mean age was 65.4 ± 10.3 year, and 36.5% of patients had prior coronary artery bypass graft. Overall, 41 patients (4.1%) suffered MACE, 9 (0.9%) mortality, 26 (2.6%) acute MI, and 11 (1.1%) required pericardiocentesis. Technical success was achieved in 86.3%. Patients who experienced MACE had higher anatomic complexity, and more often required antegrade dissection/reentry and the retrograde approach. Increasing PROGRESS‐CTO MACE scores were associated with increasing MACE rates: 0.5% (score 0−1), 2.4% (score 2), 3.7% (score 3), 4.5% (score 4), 7.8% (score 5), 13.0% (score 6−7). The AUC were as follows: MACE 0.72 (95% confidence interval CI: 0.66−0.78), mortality 0.79 (95% CI: 0.66−0.95), pericardiocentesis 0.71 (95% CI: 0.60−0.82), and acute MI 0.57 (95% CI: 0.49−0.66). Calibration was adequate for MACE and mortality, while the models underestimated the risk of pericardiocentesis and acute MI.
Conclusions
In a large external cohort of patients treated with the hybrid algorithm by experienced CTO operators, the PROGRESS‐CTO MACE, mortality, and pericardiocentesis risk scores showed good discrimination, while the acute MI score had inferior performance.
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