Role of homocysteine & MTHFR C677T gene polymorphism as risk factors for coronary artery disease in young Indians.

Background & objectives: Hyperhomocysteinaemia (HCA) either due to mutation of MTHFR gene or deficiency of vitamin B12 and folic acid, has been reported as a risk factor for coronary artery disease (CAD). The present study was aimed to determine plasma homocysteine (Hcy) levels and to evaluate MTHFR C677T gene polymorphism as risk factors for CAD, and to study the role of Hcy in conjunction with a few other risk factors of CAD in young Indians. The effect of vitamin B12 and folic acid supplements on the raised plasma Hcy levels in patients of CAD was also assessed. Methods: The present study included 199 consecutive angiography confirmed CAD patients, <45 yr of age, without any other known pro- coagulant state and 200 age- and sex-matched healthy controls. Fasting blood samples were collected in EDTA and plasma Hcy was estimated by ELISA test and the MTHFR C677T polymorphism detection was carried out by PCR-RFLP method. Results: Significant difference (P<0.001) was found between mean fasting levels of plasma Hcy in cases (22.14 ± 10.62 μmol/l) and controls (17.38 ± 8.46 μmol/l) with an Odds ratio as 1.93 (95% CI, 1.27-2.94). Levels of cholesterol, LDL, and triglycerides were significantly (P<0.001) higher in cases compared with controls. Interpretation & conclusions: Our study showed significant correlation between hyperhomocysteinaemia and coronary artery disease. Multivariate analysis by logistic regression of the various risk factors of CAD, found high levels of Hcy, cholesterol, LDL and low levels of HDL and smoking as independent predictors of CAD when all other factors were controlled. Significant post-treatment decrease found in HCA was easily modifiable by vitamin intervention irrespective to their CT or TT genotype of C677T MTHFR gene. Further studies to look at the plasma levels of folate and cobalamines and their association with Hcy are required to be done.

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.