Impact of Regional Systems of Care on Disparities in Care Among Female and Black Patients Presenting With ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: The American Heart Association Mission: Lifeline STEMI (ST-segment-elevation myocardial infarction) Systems Accelerator program, conducted in 16 regions across the United States to improve key care processes, resulted in more patients being treated within national guideline goals (time from first medical contact to device: <90 minutes for direct presenters to hospitals capable of performing percutaneous coronary intervention; <120 minutes for transfers). We examined whether the effort reduced reperfusion disparities in the proportions of female versus male and black versus white patients. METHODS AND RESULTS: In total, 23 809 patients (29.3% female, 82.3% white, and 10.7% black) presented with acute STEMI between July 2012 and March 2014. Change in the proportion of patients treated within guideline goals was compared between sex and race subgroups for patients presenting directly to hospitals capable of performing percutaneous coronary intervention (n=18 267) and patients requiring transfer (n=5542). The intervention was associated with an increase in the proportion of men treated within guideline goals that presented directly (58.7-62.1%, P=0.01) or were transferred (43.3-50.7%, P<0.01). An increase was also seen among white patients who presented directly (57.7-59.9%, P=0.02) or were transferred (43.9-48.8%, P<0.01). There was no change in the proportion of female or black patients treated within guideline goals, including both those presenting directly and transferred. CONCLUSION: The STEMI Systems Accelerator project was associated with an increase in the proportion of patients meeting guideline reperfusion targets for male and white patients but not for female or black patients. Efforts to organize systems of STEMI care should implement additional processes targeting barriers to timely reperfusion among female and black patients.

Coronary Angioplasty.

Percutaneous revascularization is a widely accepted procedure to treat patients with coronary artery disease. Since its first description in the 1970s, significant technological and pharmaceutical advances have occurred and subsequently reduced the complications associated with the procedure. Large, randomized controlled trials have provided additional evidence that percutaneous revascularization improves morbidity and mortality in patients with coronary artery disease. Over the last decade, devices designed to treat patients with more complex coronary artery disease have expanded the available therapeutic options and will likely contribute to a further decline in adverse events. Despite these advances, the management of patients with acute myocardial infarction, in-stent restenosis, and multivessel coronary artery disease remains challenging. The majority of evidence supports an early, aggressive approach in patients with acute ST-elevation and non-ST-elevation myocardial infarction. Ongoing clinical trials should help to further define the role of percutaneous interventions in the optimal management of patients with coronary artery disease.

Optimal deployment of third-generation stents: an intravascular ultrasound assessment.

Third-generation intracoronary stents allow deployment at higher pressures, possibly obviating the need for high-pressure postdilations and also possibly reducing restenosis. This study evaluated the ability of the Tristar Coronary Stent System to produce optimal stent deployment as measured by intravascular ultrasound (IVUS) and quantitative coronary angiography in 46 patients. Optimal stent deployment was defined as minimal luminal area > 80% of the average of the proximal and distal reference luminal areas. After initial deployment, 74.5% of stents met criteria for optimal stent deployment by IVUS, with an average stent expansion ratio of 89.6%. Ten stents (18.2%) were postdilated. Four patients (8.7%) had a major adverse cardiac event, one patient died, one patient had a myocardial infarction, and two patients had target vessel revascularization at 6 months. The Tristar stent system produces optimal deployment without the need for routine postdilation and results in optimal clinical outcomes.

Polyethylene glycol diisocyanate decreases platelet deposition after balloon injury of rabbit femoral arteries.

BACKGROUND: Platelet deposition after angioplasty remains problematic and may contribute to intimal hyperplasia and restenosis. We proposed that polyethylene glycol diisocyanate (PEG-DISO), a polymer that rapidly forms covalent linkages with amine residues on proteins, could mask thrombogenic vascular wall proteins from platelets, thereby abrogating acute platelet deposition. METHODS AND RESULTS: To test this hypothesis, we isolated the femoral arteries of 10 New Zealand White rabbits and injured them with 3 passes of a 2F Fogarty catheter which was inserted through a distal arteriotomy. Immediately after balloon injury, (111)indium-labeled autologous platelets were infused peripherally and the injured femoral arteries were randomly treated for 1 minute with a PEG-DISO solution in one artery and a control solution of the phosphate buffered saline vehicle in the contralateral artery. Following treatment, reflow was initiated. The vessels were harvested after 1 hour and radioactivity was quantified in a gamma counter. Platelet counts were standardized by weight and expressed as platelets/mg (mean +/- SEM). Platelet deposition onto arteries treated with PEG-DISO was (1.2 +/- 0.5) x 10(6) platelets/mg compared to (5.6 +/- 4.2) x 10(6) platelets/mg onto the contralateral control arteries treated with vehicle (P < 0.005). Scanning electron micrographs of the injured vessel segment confirmed qualitatively less platelet deposition on the treated segments than on the control segments. CONCLUSION: Treatment with PEG-DISO significantly inhibited platelet deposition after vascular injury. These data support the hypothesis that treatment with PEG-DISO masks surface adhesive proteins from platelet receptors in vivo and that the resulting molecular barrier significantly reduces platelet deposition onto the damaged vessel wall for at least one hour. The formation of a molecularly thin barrier to platelet deposition may thus be a novel and effective treatment to abrogate acute intravascular thrombosis and may have value in the treatment of restenosis.

Four-dimensional analysis of cyclic changes in coronary artery shape.

The objective of this study was to derive a method for quantifying the dynamic geometry of coronary arteries. Coronary artery geometry plays an important role in atherosclerosis. Coronary artery geometry also influences the performance of coronary interventions. Conversely, implantation of stents may alter coronary artery geometry. Clinical tools to define vessel shape have not been readily available. Using a Frenet-Serret curvature analysis applied to 3D reconstruction data derived from standard coronary angiograms, 21 coronary arteries were analyzed at end-diastole (ED) and end-systole (ES). Vessels were divided anatomically: type 1 consisted of vessels lying in the AV groove (left circumflex, right coronary) and type 2 consisted of vessels overlying actively contracting myocardium (left anterior descending, diagonal, obtuse marginal, right ventricular marginal, posterior descending, posterolateral). Vessel segments were analyzed by assessing the changes in curvature, torsion, and discrete flexion points (FPs), areas of systolic bending in the arterial contour. The curvature from ED to ES of type 1 vessels was unchanged (-0.02 +/- 0.03 cm(-1)), while the curvature change of type 2 vessels showed a 38% increase (0.33 +/- 0.04 cm(-1); P < 0.001). Type 1 vessels had fewer FPs per vessel than type 2 vessels (0.38 +/- 0.18 and 2.40 +/- 0.23 FP/vessel, respectively; P < 0.001). FPs were more common in distal segments and branch vessels. A method to quantify cyclic changes in coronary artery shape was applied to 3D data sets derived from standard coronary angiograms. Coronary arteries undergo a cyclic change in shape resulting in changes in overall curvature as well as formation of discrete flexion points. These changes in vessel shape are asymmetrically distributed in coronary arteries.