[The practical clinical guidelines of the Sociedad Española de Cardiología on interventional cardiology: coronary angioplasty and other technics]

Desarrollo de software para la reconstrucción tridimensional y cuantificación automática de secuencias de ultrasonido intravascular. Experiencia inicial

INTRODUCTION AND OBJECTIVES

Quantification of intravascular ultrasound (IVUS) images is essential in ischemic heart disease and interventional cardiology. Manual analysis is very slow and expensive. We describe an automated computerized method of analysis that requires only minimal initial input from a specialist.

METHODS

This study was carried out by interventional cardiologists and biomedical engineers working in close collaboration. We developed software in which it was necessary only to identify the media-adventitia boundary in a few images taken from the whole sequence. A three-dimensional reconstruction was then generated from each sequence, from which measurements of areas and volumes could be derived automatically. In total, 2300 randomly selected images from video sequences of 11 patients were analyzed.

RESULTS

Results obtained using the proposed method differed only minimally from those obtained with the manual method: for vessel area measurements, the variability was 0.08 (0.07) (mean absolute error [standard deviation] normalized to the actual value; this corresponds to an error of 0.08 mm(2) per mm(2) of vessel area); for lumen area, 0.11 (0.11) (normalized), and for plaque volume, 0.5 (0.3) (normalized). Regions with severe lesions (<4 mm(2)) were correctly identified in more than 90% of cases. Specialist time needed for each reconstruction was 10 (8) minutes (vs 60 [10] minutes for manual analysis; P< .0001).

CONCLUSIONS

The computerized method used dramatically reduced the time and effort needed for IVUS sequence analysis, and the automated measurements obtained were very promising.

[Coronary angioplasty in diabetic patients. Current and future perspectives]

It has been estimated that 15-25% of patients who undergo percutaneous or surgical coronary angioplasty are diabetics. The indications for coronary revascularization and initial results of the procedure do not differ substantially between patients with diabetes mellitus and non-diabetics. However, the long-term results of both percutaneous and surgical coronary angioplasty are less favorable in diabetics in terms of mortality and the need for new revascularization procedures. The development and widespread use of stents and glycoprotein IIb/IIIa receptor inhibiting drugs have improved the clinical evolution of diabetics treated with angioplasty. Currently available data show that the administration of glycoprotein IIb/IIIa inhibitors to patients undergoing coronary angioplasty is especially useful in diabetics and improves short-term and long-term results, decreasing one-year mortality by 45%. There seem to be indications for the routine use of glycoprotein IIb/IIIa inhibitors in diabetics treated with angioplasty. While the use of stents has improved long-term and short-term results in diabetics, the success rates of angioplasty in diabetics are still lower than in non-diabetics. Diabetes is still an independent predictor of restenosis and long-term events after stenting interventions. Analysis of the studies comparing percutaneous and surgical revascularization in diabetic patients with multivessel disease shows that surgery is superior in terms of long-term mortality and need for new revascularization procedures. Stenting has improved, but not substantially, the results of multivessel angioplasty in diabetics. Therefore, the indications for angioplasty in multivessel diabetics should be evaluated individually. Factors that contribute to the less favorable post-angioplasty evolution of diabetic patients are more rapid progression of atherosclerosis and, especially, a higher rate of restenosis. New angioplasty techniques, such as brachytherapy and drug-eluting stents, are likely to significantly improve the results of percutaneous interventions in diabetics, thus allowing the indications for angioplasty in diabetics to be extended even further in the near future.

[Direct Stenting without Predilation: a Single-Center Experience with 1,000 Lesions]

INTRODUCTION

Direct stenting has been shown to save costs, procedural time, radiation, and contrast use. We analyze the results of direct stenting in daily practice.

MATERIAL AND METHODS

We retrospectively analyzed the interventions in the first 1,000 lesions that were treated with direct stenting at our center. Primary success, dissection, need for additional dilation, embolism, stent loss, and side branch occlusion were the variables assessed.

RESULTS

Direct stenting was attempted in 1,000 lesions in 784 patients (age 63 11 years, females 21%, diabetes 37%). Primary or rescue angioplasty was performed in 8%. One or more thrombi were found in 16%, bifurcation in 9%, calcification in 5%, angulation in 2.3%, and tortuosity in 3.2%. The reference diameter was 3.0 0.5 mm. The primary success rate was 93.1%. Failure of direct stenting (6.9%) was associated with the circumflex artery in 38%, calcification in 26%, angulation in 22%, and tortuosity in 31%. In 39 lesions, additional dilation with different balloons was required. Additional stenting was required for dissection in 40 lesions and secondary to incomplete coverage of the lesion in 27. Thrombus embolism occurred in 7 lesions, 6 of them with a previously visible thrombus and one in a vein graft. Stent embolisms occurred in 6 cases, 4 of which were retrieved. Four side branches became occluded, but 2 of them were recovered at the end of the procedure.

CONCLUSIONS

Direct stenting is a safe technique with low percentage of dissection, need for postdilation, thrombus embolism, and side br

[Long-term follow-up of patients with proximal left anterior descending coronary artery stenosis treated with stent]

INTRODUCTION AND OBJECTIVE

Patients with lesions of the proximal left anterior descending coronary artery are a special high-risk group. In the present study we analyzed the efficacy and safety of coronary stenting in such lesions and the factors related to a less favorable prognosis in long-term follow-up.

METHODS

Ninety-eight consecutive patients with severe left anterior descending artery stenosis were enrolled, all with coronary angioplasty and elective stenting. Clinical follow-up was carried out annually in all patients by personal interview or telephone contact. The incidence of death, new infarction, anginal status, and new revascularization procedures was registered. Clinical, angiographic, and procedural variables were analyzed to identify predictors of long term prognosis.

RESULTS

Mean follow-up was 38 11 months. There was only one major periprocedural complication, which required urgent surgery. Five deaths were registered, 3 of non-cardiac and 2 of cardiac origin. Twenty-five patients developed angina and 11 underwent a new revascularization of the proximal left anterior descending coronary artery (6 surgical and 5 angioplasty). Two patients had new anterior myocardial infarction. At 60 months the major cardiac event-free rate was 83.7% and the cardiac death-free rate was 98%. The use of two stents and the association of diabetes-hypertension-hypercholesterolemia were associated with a less favorable prognosis in our population.

CONCLUSIONS

Stenting of left anterior descending coronary stenosis was safe and effective in a long-term analysis. The survival rate was high and the incidence of new revascularization was low.

[Clinical utilization of the coronary pressure wire]

INTRODUCTION

Earlier studies have established the value of coronary pressure wires for diagnosing and monitoring the treatment of patients with coronary artery disease. In this study we demonstrated their usefulness in the daily clinical practice of a catheterization laboratory.

MATERIAL AND METHODS

A retrospective study of the use of pressure wires in our laboratory between October 1998 and November 2000. The pressure wire was inserted whenever the interventional cardiologist considered it to be indicated. In all cases, pressures were recorded with a Waveguide Cardiometrics 0.014 guide (Endosonics) and hyperemia was induced by intracoronary adenosine.

RESULTS

Two hundred fifty-three lesions were studied in 190 patients. Indications were functional evaluation of lesions of intermediate severity for 82% (9% intrastent restenoses); guidance of balloon PTCA for 5%; and fulfillment of a research protocol for 13%. Twenty-six percent of lesions considered to be of moderate severity based on angiography were treated as a consequence of the pressures measured by the wire. A decision to begin or continue a procedure was based on wire pressures in 24% and intervention was avoided in 60%. No major complications attributable to the wire were observed. A lesion was dissected in one patient (0.5%) but it was treated without consequences. Twenty pressure wires (11%) failed to work properly during the procedure, fourteen of them (7%) before insertion. The wire could not be advanced across the lesion in one case.

CONCLUSIONS

The pressure wire is useful in the daily clinical practice of a catheterization laboratory. Its most common indication is the evaluation of lesions of intermediate or unknown severity, and use is associated with few complications.