Subodh Devabhaktuni has completed internal medicine residency at University of Nevada School of Medicine, Las Vegas, NV. He is currently doing cardiology fellow at University of Nevada School of Medicine, Las Vegas, NV.
Introduction: Dabigatran is a new oral anticoagulant, a direct thrombin inhibitor approved for use in non- valvular atrial fibrillation and pulmonary embolism management. It was associated with statistically non-significant increase in risk of MI in several trials. Previous study showed that TRAP (thrombin receptor- activated peptide) mediated platelet aggregation is less with both dabigatran and warfarin, but there was less inhibition of platelet aggregation by dabigatran compared to warfarin. To our knowledge no study has reported the effect of dabigatran and warfarin on PRU (platelet reactivity unit) values assessed by point of care VerifyNow P2Y12 test. Hypothesis: We hypothesized that the trend towards increased MI events in patients receiving Dabigatran could be due to an increase in platelet reactivity as measured by the VerifyNow P2Y12 test. Methods: This is a proof of concept study. We enrolled 40 patients who have been on dabigatran or warfarin for at least 6 months into one of the two study arms: Dabigatran arm or Warfarin arm. Platelet reactivity was measured by Accriva’s VerifyNow device and the PRU values were recorded. Analysis was done using Student t-test. Results: The mean PRU value in Dabigatran group was 222.4 with SD of 35.19.The mean PRU value in Coumadin group was 235.25 with SD of 34.49. T value was 1.498.Two-tailed P value was 0.25 with 95 CI ranging from -35.47 to 9.77. Conclusion: Platelet reactivity assessed by Verify Now did not differ in the two groups. These findings do not explain the observed trend in increased events of MI in the large clinical trials with dabigatran.
Ali Hasan is a graduate of the Aga Khan University, Karachi, aspiring to gain a residency in pediatrics in the United States. He holds a special interest in pediatric cardiology and hopes that the impact of his research can be used for the benefit of pediatric patients world wide. He has also authored studies detailing the use of improved techniques to treat neonatal jaundice as well as an assessment of awareness of cardiovascular risk factors.
Tetralogy of Fallot (TOF) is a common congenital heart disease. Coronary catheterization is considered to be an important diagnostic step before surgical correction. Prevalence of abnormal coronaries in TOF is up to 9%. Coronary abnormalities are difficult to delineate intra-operatively because of thick epicardial fat layer and adhesions after surgical shunting. The retrospective study was conducted in a tertiary care center in Lahore, Pakistan, to find out coronary abnormalities in TOF. Patients selected were 9 months to 16 years of age and catheterization was conducted before surgical repair. Non-selective aortic root angiograms were done, which were standard 45 left anterior oblique (LAO) and 20 cranial and 30 right anterior oblique views (RAO). Total of 662 patients with TOF underwent catheterization. 65.4% were male while 34.6% were female. 94.4% of patients with TOF had normal coronary anatomy while 5.6% of patients with TOF had abnormal anatomy. Most commonly detected abnormality was single origin of coronary artery found in 2.9% of cases (1.8% of patients had common origin from left sinus and 1.1% of patients had common origin from right sinus). Apart from the abnormality with single origin of coronary artery, 2.6% of patients had abnormal coronary with a conal branch crossing right ventricular outflow track (RVOT) anteriorly and 0.2% of patients with abnormal coronaries had conal branch crossing RVOT posteriorly. Coronary abnormalities in TOF were detected in 5.6% of the cases. Single origin coronary artery was the most common abnormality.