Ultrasound study of the prevalence of plaque at the carina in lesions that affect the coronary bifurcation. Implications for treatment with provisional stent.

INTRODUCTION AND OBJECTIVES: The plaque distribution patterns in coronary bifurcation lesions are not well understood. It has been speculated that carina is free of plaque partly because of high wall shear stress providing an atheroprotective effect. To study plaque distribution with intravascular ultrasound (IVUS) in the coronary bifurcation and the prevalence of carina involvement. METHODS: IVUS study was performed on 195 coronary bifurcation lesions in the main vessel (MV) and on 91 in the side branch (SB). Plaque at the carina was considered when its thickness was > 0.3mm. Plaque burden was measured at different levels: proximal reference, distal, carina and at the point of minimal lumen area (MLA). RESULTS: The prevalence of plaque at the carina was 32%. Its thickness was 0.8 (0.36) mm, less than that observed at the counter-carina [1.22 (0.54) mm; P<.01]. The prevalence was higher (52%) when the MLA point was distal to the carina. The plaque at the carina was associated with a lower incidence of damage at the SB ostium after stenting the MV (32% vs 54%; P<.04). CONCLUSIONS: The carina is not immune to atherosclerosis, showing plaque at this level in one third of the bifurcations. The incidence of plaque is higher in those bifurcations with the MLA point distal to the carina and seems to be associated with a lower incidence of damage to the SB ostium.

Vulnerable carina anatomy and ostial lesions in the left anterior descending coronary artery after floating-stent treatment.

INTRODUCTION AND OBJECTIVES: Percutaneous coronary intervention for ostial lesions of the left anterior descending coronary artery (LAD) remains a complex procedure. The aim of this study was to evaluate the usefulness of a method of treatment that we have termed the floating-stent approach. METHODS: The study involved 71 patients with ostial LAD lesions who underwent implantation of a drug-eluting stent in the LAD, which totally or partially covered the ostium of the circumflex artery. No further interventions were planned. Intravascular ultrasound was performed both at baseline and after treatment in 49 patients. All were followed up clinically (16+/-12 months). RESULTS: Angiography of the LAD demonstrated an immediate success rate of 100%. However, significant focal damage was observed in the circumflex ostium in 7 (10%) patients, three of whom needed treatment. The mean protrusion of the stent over the origin of the circumflex artery was 2.48+/-0.91 mm. The only predictor of circumflex ostial injury identified in the study was the carina having a spiky appearance on intravascular ultrasound, visible in the longitudinal view. We termed this feature the "eyebrow sign". Carina displacement was responsible for the focal damage in 13 of the 14 patient with this feature. Overall, the major cardiac adverse event rate during follow-up was 4%. CONCLUSIONS: Use of the floating-stent technique for treating LAD ostial lesions was straightforward and gave excellent medium-term RESULTS: Intravascular ultrasound showed that patients who had a carina with specific vulnerable anatomical features were predisposed to circumflex artery ostial injury.

Usefulness of hyperemic venous return angiography for studying coronary venous anatomy prior to cardiac resynchronization device implantation.

INTRODUCTION AND OBJECTIVES: Implantation of electrodes via the coronary sinus (CS) can be very challenging because access to the target vessel is restricted by anatomical obstacles. Consequently, prior knowledge of coronary venous anatomy is crucial. The objective of this study was to evaluate the usefulness of hyperemic venous return angiography relative to that of occlusive retrograde venography prior to cardiac resynchronization device implantation. METHODS: Coronary venous anatomy was studied in 200 patients both by videoing venous coronary return, which was optimized by inducing hyperemia, and by occlusive venography. The visibility of different portions of the coronary venous system was scored. RESULTS: Overall, sufficient anatomic information was obtained in 99.5% of patients. Visibility scores for the CS and the lateral vein of the left ventricle were slightly higher in the group studied using occlusive venography, though there was no significant difference between the two techniques. In contrast, the middle cardiac vein and the anterior interventricular vein could be visualized in greater detail using venous return angiography. There were no complications in the group studied using venous return angiography whereas dissection of the great cardiac vein occurred in three patients studied using occlusive venous angiography, though this did not prevent electrode implantation. CONCLUSIONS: With venous return angiography, it was possible to visualize accurately the venous anatomy of the lateral wall of the left ventricle and, consequently, to anticipate the level of difficulty posed by electrode implantation.

[Late failure of left ventricular leads stabilized using the retained guidewire technique in patients undergoing cardiac resynchronization therapy]. / Deterioro tardío del electrodo venoso ventricular izquierdo estabilizado con la técnica de la guía retenida para la terapia de resincronización cardiaca.

The retained guidewire technique has been proposed as an alternative method for stabilizing the left ventricular lead in patients who experience repetitive intraoperative dislocation. This article concerns three patients, out of a total of 185 (1.6%) undergoing cardiac resynchronization therapy, who had to be treated using the retained guidewire technique because of demonstrable recurrent lead dislocation. Electrode parameters were all within normal limits. Although lead dislocation could not be demonstrated macroscopically, sensing and pacing parameters were found to have changed 6 months to 1 year after implantation, with a marked elevation in impedance. Laboratory analysis showed deformation and fracture of the coil electrodes as well as deterioration of the insulation coating. In conclusion, our experience shows that the retained guidewire technique should not be used because delayed electrode damage can occur.

Ultrasound findings during percutaneous treatment of bifurcated coronary lesions.

INTRODUCTION AND OBJECTIVES: Provisional stenting has been shown to be effective in the treatment of bifurcated coronary lesions. The aim of this study was to evaluate changes in the geometry of the main vessel stent following side branch (SB) dilatation and kissing balloon (KB) inflation. METHODS: The study involved 23 patients with a bifurcated coronary lesion. A first intravascular ultrasound (IVUS) study was performed after drug-eluting stent implantation in the main vessel. Subsequently, angioplasty of the SB was carried out, and a second IVUS was performed to evaluate its effect. Finally, KB inflation was carried out, followed by a third IVUS study of the main vessel. The cross-sectional area of the implanted stent at different points was compared in the three IVUS studies. RESULTS: The cross-sectional area of the proximal segment of the recently implanted stent was 7.3+/-1.9 mm2 and increased to 9.6+/-2.9 mm2 after KB inflation (P< .05). Dilatation of the SB resulted in a reduction in the cross-sectional area under the SB origin from 5.9+/-1.2 mm2 initially to 5.2+/-1.2 mm2 (P< .05). After KB inflation, the cross-sectional area partially recovered (to 5.6+/-1.2 mm2). CONCLUSIONS: After angioplasty of the SB, a reduction was observed in the cross-sectional area of the stent immediately distal to the SB origin. The area did not return to its initial value after KB inflation. However, KB inflation increased the cross-sectional area of the proximal segment of the stent and changed stent geometry.

[Double-wire technique for implanting a left ventricular venous lead in patients with complicated coronary venous anatomy]. / Técnica de la doble guía para el implante del electrodo venoso ventricular izquierdo en pacientes con anatomía venosa coronaria desfavorable.

INTRODUCTION AND OBJECTIVES: Occasionally, implanting a left ventricular pacing electrode for cardiac resynchronization therapy via the coronary sinus may be complicated by the presence of anatomical structures that obstruct the access to the target vein. Our objective was to report on experience using a double-wire technique for implanting left ventricular venous leads gained at the Dr Negrín Hospital in Gran Canaria, Spain. METHODS: In 20 (12%) of 170 consecutive patients (67 [9] years, 72% male) undergoing implantation of a cardiac resynchronization device, a second parallel hydrophilic guidewire had to be used during lead implantation in the target vein as implantation was impossible without using this technique. RESULTS: Implantation using a conventional approach was impossible because there was severe tortuosity at the vessel entrance in five patients (25%), a sharp angle at the entrance to the target vein in seven (35%), a venous valve at the vessel entrance in eight (40%), and, finally, poor support for the guiding catheter in four (20%), due to the presence of either a fenestrated Thebesian valve (two patients) or a restrictive Vieussens valve (two patients) that blocked passage of the guiding catheter or electrode. In four patients (20%), there was more than one factor. In all these cases, implantation was achieved in the target vein without complications after passage of a second hydrophilic guidewire. CONCLUSIONS: The use of a second parallel guidewire (i.e., the double-wire technique) provides a safe and effective way of implanting left ventricular venous pacing electrodes in patients with anatomical complications.