Comparison of a rapid point-of-care and two laboratory-based CYP2C19*2 genotyping assays for personalisation of antiplatelet therapy.

BACKGROUND: A quick CYP2C19*2 genotyping assay can be useful in personalised antiplatelet-therapy. OBJECTIVE: To apply a rapid point-of-care (POC) CYP2C19*2 genotyping assay for personalisation of antiplatelet therapy in patients undergoing percutaneous coronary intervention (PCI) and to compare this POC assay to two laboratory-based CYP2C19*2 genotyping assays. SETTING: Cardiac Catheterisation Suite and Molecular Diagnostics Unit in a general hospital. METHODS: A buccal sample was collected for POC CYP2C19*2 genotyping with the Spartan™ RX system (Spartan Bioscience). A whole blood sample was collected from the same patients for laboratory-based CYP2C19*2 genotyping with a TaqMan® allelic discrimination assay (Life Technologies) using real-time quantitative PCR and with the GenID® reverse dot-blot hybridisation assay (Autoimmun Diagnostika GmbH). Each patient was genotyped as a non-carrier of CYP2C19*2 (*1/*1), a carrier of one CYP2C19*2 allele (*1/*2), or a carrier of two CYP2C19*2 alleles (*2/*2). Genotyping, interpretation and communication of genotype results (*1/*2, *2/*2) to the consultant cardiologist was undertaken by a clinical pharmacist researcher. Quantitative and qualitative comparison between the three assays was carried out. MAIN OUTCOME MEASURES: Application of a rapid POC CYP2C19*2 genotyping assay for antiplatelet therapy individualisation; comparison of the POC CYP2C19*2 genotyping assay to two laboratory-based assays. RESULTS: The total sample consisted of 34 Caucasian patients. With the POC assay, 21 patients were genotyped as non-carriers of CYP2C19*2, 12 patients as carriers of one CYP2C19*2 allele and one patient as a carrier of two CYP2C19*2 alleles. With both laboratory-based assays, the same 21 patients were genotyped as non-carriers of CYP2C19*2, however 13 patients were genotyped as carriers of one CYP2C19*2 allele and no patients were genotyped as carriers of two CYP2C19*2 alleles. Agreement in genotype results was 97 % (κ = 0.939) between the POC assay and both laboratory-based assays and 100 % (κ = 1.000) between the two laboratory-based assays. CONCLUSION: Compared to both laboratory-based genotyping assays, the POC assay is accurate and reliable, provides rapid results, can process single samples, is portable and more operator-friendly, however the tests are more expensive.

A comparison between dual axis rotational coronary angiography and conventional coronary angiography.

BACKGROUND: Coronary angiography remains the gold standard for the investigation of coronary artery disease, and is carried out in multiple, predefined stationary views, at different angulations around the patient, for both left and right coronary arteries. Dual axis rotational coronary angiography (DARA) is an alternative technique wherein the c-arm rotates around the patient in a preprogrammed single acquisition, exposing the entire coronary artery at different angulations. The DARA system has been recently installed in the Cardiac Catheterisation Suite at Mater Dei Hospital, Malta, where a monoplane and a biplane machine are available. This study was carried out in order to compare DARA with conventional single and biplane coronary imaging, with respect to radiation dose, contrast loads, and procedure time. METHODS: This study was carried out over the period from September to December 2010. Four hundred sixty-three patients were studied. Patients referred for the investigation of native coronary anatomy, for whatever indication, were consented and included, and randomly assigned to one of four groups depending on which machine and modality was used: monoplane conventional, monoplane DARA, biplane conventional, and biplane DARA. RESULTS: DARA was statistically significantly superior in dose area product, fluoroscopy time, amount of contrast used, and procedure time. These reductions ranged between 12 (contrast used) and 71% (procedure time). CONCLUSIONS: The advantages of such systems are obvious to both patient and healthcare provider, and DARA may prove to be an important and useful tool in the refinement of diagnostic coronary angiography by reducing patient contrast and radiation doses and reducing procedure time.

Broken heart during treadmill exercise testing: an unusual cause of ST-segment elevation.

Treadmill exercise testing is a commonly used diagnostic test for the assessment of chest discomfort and exercise-induced arrhythmias. The presence of ST-segment elevation during exercise is considered a marker of severe ischaemia, usually secondary to a critical lesion in a proximal coronary artery. We present a novel cause of ST-segment elevation during exercise testing: "broken heart syndrome", also known as transient left ventricular apical ballooning syndrome, or takotsubo cardiomyopathy. Takotsubo cardiomyopathy is a rare, yet well-described, reversible cardiomyopathy triggered by profound psychological or physical stress. The exact aetiology of takotsubo cardiomyopathy is still unknown. However, the occurrence of takotsubo cardiomyopathy during exercise in this case report is in keeping with the sudden catecholamine surge secondary to treadmill exercise testing, which leads to abnormal ventricular contraction and contributes to wall motion abnormalities. Further studies are needed to elucidate the pathogenesis of the disease and consequently determine specific preventive therapies.