Comparison of men versus women in cross-sectional area luminal narrowing, quantity of plaque, presence of calcium in plaque, and lumen location in coronary arteries by intravascular ultrasound in patients with stable angina pectoris.

Women have an increased mortality after coronary interventions compared with men, which may be partly explained by differences in comorbid clinical conditions. However, whether women also have quantitative differences in coronary atherosclerosis is not known. Preinterventional intravascular ultrasound (IVUS) was used to study de novo, nonostial native coronary lesions in 169 women and 549 men with chronic angina.

Intravascular Ultrasound Assessment of the Mechanisms and Predictors of Restenosis Following Coronary Angioplasty.

Restenosis occurs after 30% to 50% of transcatheter coronary procedures; its mechanisms remain incompletely understood. Intravascular ultrasound (IVUS) studies were analyzed in 360 nonstented native coronary artery lesions in which follow-up quantitative angiographic and/or IVUS data was available. Pre-intervention, post-intervention, and follow-up, the external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque+media (P+M=EEM Ð lumen CSA), and cross-sectional narrowing (CSN=P+M/EEM CSA) were calculated.

Contribution of inadequate arterial remodeling to the development of focal coronary artery stenoses. An intravascular ultrasound study.

Background: Adaptive remodeling occurs to compensate for the accumulation of atherosclerotic plaque. Lumen reduction depends on the relative rates of plaque deposition and adaptive remodeling responses. Intravascular ultrasound permits detailed, high-quality, cross-sectional imaging of the coronary arteries in vivo.

Serial intravascular ultrasound predictors of restenosis at the margins of Palmaz-Schatz stents.

To evaluate predictors of restenosis at margins of Palmaz-Schatz stents, intravascular ultrasound studies were performed after intervention and at follow-up (5.4 months) in 161 stented lesions. Of 301 stent margins, 77 (26%) were restenotic at follow-up (>50% late lumen loss).

Increased restenosis in diabetes mellitus after coronary interventions is due to exaggerated intimal hyperplasia. A serial intravascular ultrasound study.

Background: The increased risk of restenosis after catheter-based coronary interventions in diabetic patients has not been determined. Intravascular ultrasound (IVUS) has shown that the decrease in arterial area is responsible for most of the late lumen loss in nonstented lesions and that intimal hyperplasia is responsible for all of the late lumen loss in stented lesions.

Methods And Results: Serial (postintervention and follow-up at 5.

Influence of guiding catheter selection on the measurement of coronary flow reserve.

The impact of guiding catheter selection on the measurement of coronary flow reserve was assessed by injecting increasing doses of adenosine through 3 different catheters often used during coronary interventions. When guiding catheters with side holes were used, an approximate doubling of the adenosine dose was required to produce a coronary flow reserve response similar to a 12-micrograms dose of adenosine injected through guiding catheters without side holes.

Intravascular stenting as a definitive treatment of spontaneous carotid artery dissection.

We describe successful treatment with intravascular stenting of a patient with spontaneous right carotid artery dissection. This case report demonstrates the potential use of stents for treating symptomatic carotid artery dissection.

Intravascular ultrasound insights into mechanisms of stenosis formation and restenosis.

Using intravascular ultrasound (IVUS), stenosis formation and restenosis (or late lumen loss following coronary angioplasty procedures) can be subdivided into two distinct underlying components: tissue accumulation and arterial remodeling. Arterial remodeling is defined as a change in total arterial cross-sectional area over time; it can be adaptive (an increase in arterial cross-sectional area as a compensatory response to plaque accumulation) or pathologic (a decrease in arterial cross-sectional area or chronic arterial shrinkage). Adaptive arterial remodeling can delay the development of coronary artery stenoses and prevent restenosis; pathologic remodeling can contribute to de novo lesion formation and has been shown to be the dominant mechanism of restenosis following coronary intervention.

Determinants and correlates of target lesion calcium in coronary artery disease: a clinical, angiographic and intravascular ultrasound study.

Objectives: This report used intravascular ultrasound and quantitative coronary angiography to explore the relation between lesion-associated calcium and risk factors, clinical presentation and angiographic severity of coronary artery stenoses.

Background: Coronary artery calcium is a marker for significant coronary atherosclerosis. Noninvasive procedures are being proposed as screening tests for coronary artery disease.

An overview of US coronary stent trials.

Since the introduction of coronary stent procedures in the US there has been a determined effort to understand appropriate clinical applications better through the use of carefully designed prospective clinical trials. These studies fall into the general categories of efficacy studies, pharmacology, studies, intravascular ultrasound studies, adjuvant stent therapy studies, stent versus stent studies and new stent registries. Most of the pivotal clinical trials have been randomized controlled studies, but there have also been several carefully performed registry analyses which have provided useful insights.

Chronic arterial responses to stent implantation: a serial intravascular ultrasound analysis of Palmaz-Schatz stents in native coronary arteries.

Objectives: We used intravascular ultrasound (IVUS) imaging to evaluate the chronic vessel responses to Palmaz-Schatz stents.

Background: Palmaz-Schatz stents have been shown to inhibit early elastic recoil and late arterial remodeling while triggering neointimal hyperplasia. However, changes occurring in native vessels surrounding stent struts have not been well studied.

Effect of rotational atherectomy in noncalcified atherosclerotic plaque: a volumetric intravascular ultrasound study.

Objectives: This study used pre-rotational and post-rotational atherectomy volumetric intravascular ultrasound analysis to determine whether rotational atherectomy causes ablation of non-calcified atherosclerotic plaque.

Background: Rotational atherectomy is currently the preferred treatment for heavily calcified coronary lesions. However, the mechanism of lumen enlargement in noncalcified lesions has not been studied in detail.

Mechanisms and results of balloon angioplasty for the treatment of in-stent restenosis.

Restenosis within tubular slotted stents is secondary to intimal hyperplasia and is usually treated with percutaneous transluminal coronary angioplasty (PTCA). Sequential intravascular ultrasound (IVUS) was used to assess the mechanisms and results of PTCA for in-stent restenosis. Sixty-four restenotic Palmaz-Schatz stents were studied by IVUS imaging before and after PTCA.

Patterns and mechanisms of in-stent restenosis. A serial intravascular ultrasound study.

Background: Studies have suggested that restenosis within Palmaz-Schatz stents results from neointimal hyperplasia or chronic stent recoil and occurs more frequently at the articulation.

Methods And Results: Serial intravascular ultrasound (IVUS) was performed after intervention and at follow-up in 142 stents in 115 lesions. IVUS measurements (external elastic membrane [EEM], stent, and lumen cross-sectional areas [CSAs] and diameters) were performed, and plaque CSA (EEM lumen in reference segments and stent lumen in stented segments), late lumen loss (delta lumen), remodeling (delta EEM in reference segments and delta stent in stented segments), and tissue growth (delta plaque) were calculated.

Intravascular ultrasound to discern device-specific effects and mechanisms of restenosis.

Restenosis continues to be the "Achilles heel" of transcatheter interventions. While attempts to reduce restenosis by inhibiting cellular proliferation through pharmacologic or mechanical means have been unsuccessful, stents, which inhibit acute recoil and chronic remodeling, have been shown convincingly to reduce restenosis in 2 randomized clinical trials. Intravascular ultrasound (IVUS) allows transmural, tomographic imaging of coronary arteries in humans in vivo to subdivide restenosis into the two basic underlying components: tissue proliferation and arterial remodeling.

Arterial remodeling after coronary angioplasty: a serial intravascular ultrasound study.

Background: Restenosis occurs after 30% to 50% of transcatheter coronary procedures; however, the natural history and pathophysiology of restenosis are still incompletely understood.

Methods And Results: Serial (postintervention and follow-up) intravascular ultrasound imaging was used to study 212 native coronary lesions in 209 patients after percutaneous transluminal coronary angioplasty, directional coronary atherectomy, rotational atherectomy, or excimer laser angioplasty. The external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque plus media (P+M) CSA was calculated as EEM minus lumen CSA.

In vivo validation of intravascular ultrasound length measurements using a motorized transducer pullback system.

Using sonoreflective endovascular targets of known length (stainless steel tubular slotted stents), we have validated in vivo the accuracy and reproducibility of intravascular ultrasound length measurements using a system incorporating motorized transducer pullback through a stationary imaging sheath. The correlation was r = 0.936, with a measurement error of only +/- 5.

Mechanisms and immediate and long-term results of adjunct directional coronary atherectomy after rotational atherectomy.

Objectives: The purpose of this study was to confirm the mechanisms and the immediate and long-term results of rotational atherectomy and adjunct directional coronary atherectomy.

Background: Rotational atherectomy is best suited for treating calcific stenoses, but the ability of rotational atherectomy alone to optimize lumen dimensions in large vessels is limited; this is only partly improved by adjunct balloon angioplasty.

Methods: We treated 165 lesions in 163 patients by use of rotational atherectomy and adjunct directional coronary atherectomy.

Angiographic and procedural outcome after coronary angioplasty in high-risk subsets using a decremental diameter (tapered) balloon catheter. Tapered Balloon Registry Investigators.

The angiographic and clinical outcomes of 115 patients (129 lesions) treated at 11 clinical centers using a decremental diameter (tapered) balloon catheter were evaluated. The presence of marked tapering of the reference vessel, lesion location involving a bifurcation or anastomosis of a saphenous vein graft, or total coronary occlusion where estimation of the distal vessel size was difficult were indications for this device. The tapered balloon was used as the initial dilatation device in 62 patients (73 narrowings), and as a secondary device in 53 patients (56 narrowings).