Angiographic follow-up of genous bioengineered stent in acute myocardial infarction (GENAMI)-a pilot study.

OBJECTIVE: GENAMI, an angiographic follow-up study was undertaken to evaluate the safety and efficacy of a new generation endothelial progenitor cell (EPC) capture stent, GENOUS during primary angioplasty for ST-elevation myocardial infarction (MI). METHODS: Eleven consecutive patients with acute ST-elevation MI underwent primary percutaneous coronary intervention (PCI) using a bio-engineered GENOUS EPC stent. RESULTS: Procedural success was 100%. Ten patients who survived underwent a follow-up angiography at 8 months. There was no instance of stent thrombosis during the follow-up period up to 12 months. The quantitative angiographic (quantitative coronary analysis [QCA]) follow-up data showed a late loss at 8 months of 0.97 +/- 0.94 mm and the late loss index was 44.35 +/- 40.47% with angiographic restenosis seen in 5 of 10 patients (50%). One of these patients with provocable ischemia underwent repeat PCI. CONCLUSIONS: The QCA data of this study shows a high late loss with frequent angiographic restenosis during follow-up with this stent during primary PCI for acute STEMI. This observation, with important clinical implications, needs to be confirmed in larger studies.

Cobalt chromium stent with antiproliferative for restenosis trial in India (COSTAR I).

BACKGROUND: The CoStar stent is a novel cobalt chromium stent designed specifically for drug delivery. The COSTAR I trial represents the first-in-man study of the CoStar Paclitaxel-Eluting Coronary Stent System evaluating three dose release formulations of paclitaxel in a bioresorbable polymer matrix in the treatment of de novo coronary lesions. METHODS: The COSTAR I Trial was a prospective, multi-center registry enrolling 87 patients in four Indian centers for treatment of up to two de novo lesions = 25 mm in length in a reference vessel 2.5-3.5 mm in diameter. Three dose release formulations were studied: 30 microg eluted over 10 days bidirectionally (Group 1, n =10), 10 microg eluted over 30 days abluminally (Group 2, n=40) and 3 microg eluted over 30 days abluminally (Group 3, n = 37). RESULTS: Demographics and lesion characteristics were similar between the groups and treatment in all three groups included small caliber vessels (RVD 2.45 +/- 0.30 - 2.57 +/- 0.36 mm). The primary endpoint of in-stent late loss at four months was lowest in Group 2 (0.43 +/- 0.43 mm) compared to Group 1 and Group 3 (0.51 +/- 7 mn; 0.74 mm and 1.07 +/- 0.65 mm respectively). In-segment late loss followed similar trends, being lowest in Group 2 (0.24 +/- 0.39 mm) compared to Groups 1 and 3 (0.52 +/- 0.66 mm and 0.76 +/- 0.57 mm respectively). Group 2 demonstrated better angiographic out-comes at 12 months with in-stent late loss of 0.55 +/- 0.38 mm when compared to Groups 1 and 3 (0.90 +/- 0.76 mm and 0.74 +/- 0.55 mm respectively). Cumulative binary restenosis rates at twelve months were 1.9%, 35.7% and 39.1% in Groups 2, 1 and 3 respectively. Clinical outcomes trended similarly with cumulative MACE rates at twelve months being lowest at 7.5% in Group 2 as compared to 20% in Group 1 and 21.6% in Group 3 respectively. CONCLUSIONS: In this first-in-man feasibility trial, angiographic and clinical results seen with the extended release formulation at a higher dose (10 microg/30 days) demonstrate the feasibility of the CoStar stent platform in the treatment of native coronary lesions. It also demonstrates the importance of drug dose and release kinetics.

Diffuse unilateral pulmonary arteriovenous fistulae-a rare anomaly.

Diffuse pulmonary arteriovenous fistulae are rare, more so when unilateral. This article describes a 12-year-old boy with diffuse right-sided pulmonary arteriovenous fistula in whom prior percutaneous transcatheter coil occlusion has been attempted without success.The patient was subjected to ligation and transection of the right pulmonary artery and he is presently doing well.

Mahaim automatic accelerated rhythm: a marker of successful radiofrequency ablation.

BACKGROUND: Mahaim pathways are characterized by the presence of an accessory pathway potential-the 'M' potential, at the tricuspid annulus. M potential is a very useful guide during radiofrequency ablation of Mahaim pathway. During ablation, an accelerated rhythm with ORS morphology, identical to fully pre-excited QRS complex is observed, and has been labeled as Mahaim automatic rhythm. We analyzed this rhythm during radiofrequency ablation of these pathways. METHODS AND RESULTS: Eighteen patients with Mahaim accessory pathways were taken up for electrophysiology study and radiofrequency ablation. Tricuspid annulus was mapped for 'M' potentials and targeted for ablation. Duration of ablation and number of ablation attempts were guided by Mahaim automatic rhythm during ablation. Mahaim tachycardia was inducible in all. 'M' potentials were recorded in 15/18 patients. Radiofrequency energy was delivered at the site where Mahaim accelerated rhythm was noticed and was continued till abolition of the rhythm. This resulted in long-term success. In 3 patients, M potentials were not recordable, and in them other methods including 3-dimensional electroanatomical mapping was also not successful. CONCLUSIONS: 'M' potential-guided radiofrequency ablation is a useful technique. Presence of Mahaim automatic rhythm and its abolition during ablation is associated with long-term success of the procedure.

Pace mapping for the localization of focal atrial tachycardia arising near the mitral annulus.

Of the various therapeutic modalities available to treat ectopic atrial tachycardia, radiofrequency catheter ablation has shown excellent results. It is usually possible to localize the earliest site of endocardial activation by conventional or newer three-dimensional mapping techniques. We report a case of ectopic atrial tachycardia, wherein the tachycardia was being repeatedly interrupted by mechanical trauma. Finally, with the help of P wave pace mapping, the tachycardia was localized near the posterolateral part of the mitral annulus, and successfully ablated. This report demonstrates the utility of P wave pace mapping in ectopic atrial tachycardia.

Left atrial-coronary sinus dissociation following an attempt at radiofrequency ablation for a left lateral accessory pathway.

Coronary sinus electrograms generally represent the sequence of left atrial activation, and are very helpful in localizing and differentiating left lateral accessory pathway-mediated tachycardia from other supraventricular tachycardias. The activation of the coronary sinus from the left atrium occurs through muscle bridges, which may be discrete or form an intermingled continuum. These muscle bridges, if disconnected, may dissociate the coronary sinus from the left atrium, in which case the coronary sinus electrograms do not represent left atrial activation, and do not help to understand, or may cause misinterpretation of, the mechanism of supraventricular tachycardia. We report one such case of orthodromic supraventricular tachycardia mediated through the left lateral accessory pathway in which the coronary sinus got dissociated from the left atrium during radiofrequency ablation.

Sildenafil in the management of primary pulmonary hypertension.

Primary pulmonary hypertension is a rare disorder of unknown etiology with a poor prognosis. There is no cure, and drug therapy is effective in only a few patients. Calcium-channel antagonists and anticoagulants are the mainstay of therapy. Prostacyclin therapy leads to significant clinical improvement but its use is restricted due to high cost and complex drug delivery systems. Sildenafil is a selective vasodilator and has been shown to be effective in decreasing pulmonary vascular resistance in animal models of pulmonary hypertension. We report the use of sildenafil in two patients of primary pulmonary hypertension who were refractory to conventional drug therapy.