[A rare ventricular septal defect: a case report]. / Un raro difetto acquisito del setto ventricolare: caso clinico.

Left ventricular-right atrial communications, known collectively as the Gerbode defect, are rare types of ventricular septal defects. Acquired forms of this defect have been described as a complication of cardiac surgery, bacterial endocarditis, chest trauma, or myocardial infarction. Diagnosis of this rare defect is challenging, but can be confirmed with echocardiography or cardiac magnetic resonance imaging. Until 6 years ago, these communications were corrected only surgically, often with relatively high mortality. However, few case reports of transcatheter closures of the defects have recently been reported with excellent results. We describe a 69-year-old patient with left ventricular-right atrial communication secondary to mitral valve surgery. The diagnosis was made by transesophageal and real-time three-dimensional echocardiography. The defect was closed percutaneously using an Amplatzer device. At follow-up, there was no residual flow and the patient improved clinically.

[Optimal dose of bivalirudin in dialysis patients at high risk of heparin-induced thrombocytopenia undergoing percutaneous coronary intervention: case report]. / La scelta del dosaggio ottimale della bivalirudina nei pazienti in dialisi ad elevato rischio di trombocitopenia da eparina sottoposti a rivascolarizzazione percutanea: descrizione di un caso clinico.

Bivalirudin is a direct thrombin inhibitor that has been approved for use in patients with or at risk for heparin-induced thrombocytopenia undergoing percutaneous coronary intervention. The efficacy of bivalirudin has been well documented in the setting of percutaneous coronary intervention, but there are only few data on its use in chronic dialysis-dependent patients. Bivalirudin is mainly eliminated enzymatically (80%) and to a lesser extent renally (20%). Nevertheless, in patients with chronic kidney disease a substantial increase in coagulation time and bleeding complications has been reported. Therefore, dosage adjustments may be necessary in patients with renal impairment. Dosing and monitoring recommendations in dialysis patients have not yet been established. We describe the case of a 77-year-old man with non-ST-elevation acute coronary syndrome complicated by heparin-induced thrombocytopenia and acute renal failure requiring dialysis treatment. During percutaneous coronary intervention, anticoagulant therapy with bivalirudin was administered at non-standard doses, though already documented in the literature.

Genetic and nongenetic factors influencing the response to clopidogrel.

The antiplatelet drug clopidogrel is a commonly prescribed therapy in patients with acute coronary syndrome. However, its clinical efficacy is hampered by a wide inter-patient response variability, with over 30% of patients treated with this drug experiencing an inadequate antiplatelet response. There are growing evidences that clopidogrel response variability is associated with cytochrome P450 (CYP) enzyme genetic polymorphisms, primarily CYP2C19 which is responsible for the conversion of clopidogrel into its active metabolite. All of the CYP2C19 polymorphism data suggest that carriers of allele *2 or *17 are at greater risk of ischemic or bleeding events, particularly in patients with acute coronary syndrome undergoing percutaneous coronary intervention. Yet, CYP2C19 status explains only 12% of clopidogrel response variability, indicating that genetic variants other than CYP2C19 might be important. Clopidogrel undergoes intestinal efflux via P-glycoprotein, encoded by the ABCB1 gene. The C3435T polymorphism in this gene affects the bioavailability of clopidogrel, however, its effects on clinical outcomes are inconclusive. Similarly, a polymorphism in the gene encoding PON1, a rate-limiting enzyme for clopidogrel bioactivation, also affects the response to clopidogrel. Among nongenetic factors, an adverse drug interaction between proton pump inhibitors and clopidogrel is often reported, but evidence is inconclusive. A genetic test to identify potential responders to clopidogrel might be useful. However, the use of such tests is currently limited because they focus mainly on CYP2C19 loss-of-function alleles, and there is no empirical evidence yet for genotype-guided clopidogrel therapy.

Computed tomography coronary angiography in patients with acute myocardial infarction without significant coronary stenosis.

BACKGROUND: It is known that a significant number of patients experiencing an acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at coronary angiography (CA). Computed tomography coronary angiography (CTCA) can identify the presence of plaques, even in the absence of significant coronary stenosis. This study evaluated the role of 64-slice CTCA in detecting and characterizing coronary atherosclerosis in these patients. METHODS AND RESULTS: Consecutive patients with documented acute myocardial infarction but without significant coronary stenosis at CA underwent late gadolinium-enhanced magnetic resonance and CTCA. Only the 50 patients with an area of myocardial infarction identified by late gadolinium-enhanced magnetic resonance were included in the study. All of the coronary segments were assessed for the presence of plaques. CTCA identified 101 plaques against the 41 identified by CA: 61 (60.4%) located in infarct-related arteries (IRAs) and 40 (39.6%) in non-IRAs. In the IRAs, 22 plaques were noncalcified, 17 mixed, and 22 calcified; in the non-IRAs, 5 plaques were noncalcified, 8 mixed, and 27 calcified (P=0.005). Mean plaque area was greater in the IRAs than in the non-IRAs (6.1±5.4 mm(2) versus 4.2±2.1 mm(2); P=0.03); there was no significant difference in mean percentage stenosis (33.5%±14.6 versus 31.7%±12.2; P=0.59), but the mean remodeling index was significantly different (1.25±0.41 versus 1.08±0.21; P=0.01). CONCLUSIONS: CTCA detects coronary plaques in nonstenotic coronary arteries that are underestimated by CA, and identifies a different distribution of plaque types in IRAs and non-IRAs. It may therefore be valuable for diagnosing coronary atherosclerosis in acute myocardial infarction patients without significant coronary stenosis.