Amyloid Deposits in a Functionally Unicuspid Stenotic Aortic Valve.

Amyloidosis concomitant to aortic stenosis usually occurs with myocardial infiltration by the transthyretin protein. To our knowledge, this is the first report of localized amyloidosis of indeterminate type in a severely calcified and functionally unicuspid aortic valve. Isolated dystrophic valvular amyloidosis is believed to be related to fibrocalcific valve disease. In light of the literature on this topic, the present case raises new hypotheses on pathophysiology and further supports the contributory role of unusual non-tricuspid valve morphology in the development of dystrophic amyloid, likely secondary to altered hemodynamic stress.

Une amyloïdose associée à une sténose aortique survient généralement avec infiltration du myocarde par la protéine transthyrétine. Le cas que nous décrivons est, à notre connaissance, le premier cas rapporté d'amyloïdose localisée de type indéterminé dans une valve aortique sévèrement calcifiée et fonctionnellement unicuspide. L'amyloïdose valvulaire dystrophique isolée serait liée à l'atteinte fibrocalcique de la valve. À la lumière de la littérature à ce sujet, le cas décrit ici permet de soulever de nouvelles hypothèses physiopathologiques et appuie le lien entre une morphologie valvulaire inhabituelle (non tricuspide) et l'apparition de substances amyloïdes dystrophiques, probablement secondaire à une altération des contraintes hémodynamiques.

Effect of clopidogrel on bleeding and transfusions after off-pump coronary artery bypass graft surgery: impact of discontinuation prior to surgery.

OBJECTIVE: The use of antiplatelet drugs to treat acute myocardial infarction, unstable angina, acute coronary syndrome and secondary prevention following percutaneous coronary interventions is well accepted. However, it constitutes a serious risk of bleeding for patients undergoing coronary artery bypass grafting surgery (CABG). We evaluated the effect of aspirin and clopidogrel (CPDG), both irreversible platelet aggregation inhibitors, on operative bleeding and determined the optimal timing for their discontinuation before surgery. METHOD: Between July 2001 and December 2004, we reviewed our experience with 453 patients undergoing off-pump CABG surgery (OPCAB) who received CPDG (n=101) or not (n=352) preoperatively, and compared the intraoperative and postoperative bleeding to determine risks factors associated with blood or platelet transfusions. RESULTS: Clopidogrel in OPCAB surgery is associated with higher intraoperative (702.24 ml vs 554.13 ml, p=0.03) and postoperative bleeding (864.93 ml vs 603.75 ml, p=0.03). The mean operative blood loss is higher in patients still on CPDG at the time of surgery compared to patients off CPDG at least 72 h before surgery (802 ml vs 554.13 ml, p<0.0001). Blood loss in the later subgroup of patients is comparable to the control group without CPDG (p=NS). Clopidogrel is associated with more platelet transfusions (OR=11.79, [1.48; 93.86]). CONCLUSION: Blood loss is higher in OPCAB patients receiving clopidogrel before surgery. However, discontinuation of clopidogrel three days (72 h) prior to the operation demonstrated a similar blood loss pattern compared to a control group. Clopidogrel is associated with more platelets, but not red blood cell transfusions following OPCAB surgery.

Hemodynamic changes during off-pump CABG surgery.

OBJECTIVES: The purpose of this study was to assess the patients' hemodynamics during off-pump coronary artery bypass graft (OPCABG) surgery. METHODS: Continuous monitoring of the mean systemic arterial pressure (SAP), mean pulmonary arterial pressure (PAP), mixed venous oxygen saturation (SvO(2)) and cardiac output index (COI) was done on 55 patients undergoing complete OPCAB revascularization. Hemodynamic changes were recorded at the completion of the anastomosis before releasing coronary snaring and stabilization and compared to baseline. RESULTS: The mean age of the patients was 66.4+/-9.2 years, and on average 3.3+/-0.8 grafts per patient were performed. The average SAP drop after manipulations was -8.3+/-16.9 mmHg for the left anterior descending artery (LAD), -13.5+/-19.6 mmHg for the diagonal artery (DG), -14.6+/-13 mmHg for the optuse marginal artery (OM), and -14.2+/-13.5 mmHg for the right coronary artery. This was significant for all territories (P<0.01). The PAP significantly increased in all territories except OM (LAD: 3.7+/-6.3 mmHg, DG: 4.3+/-8.6 mmHg, OM: 1.1+/-7.2 mmHg, posterior descending artery: 2.7+/-5.6 mmHg; P<0.05). Variations in COI were significant in all territories (P<0.01) but more significantly in LAD and DG territories (-15+/-3% and -13+/-9%, respectively). The SvO(2) variations were <10% for all territories and reached only borderline significance (P=0.05) in all territories except OM. All these hemodynamic changes were well tolerated by all patients. CONCLUSIONS: Manipulation of the beating heart during OPCABG surgery brings significant fluctuations in the patients' hemodynamics. Mean PAP increase and COI drop were more significant during manipulation of the anterior territories suggesting a more severe diastolic restrictive disease during anterior wall manipulation.