Dimitri Kalavrouziotis

High-Dose Tranexamic Acid Is an Independent Predictor of Early Seizure After Cardiopulmonary Bypass

BACKGROUNDnRisk factors associated with early seizure after cardiopulmonary bypass (CPB) were examined. The role of tranexamic acid in seizure development was evaluated.nnnMETHODSnEarly seizure was defined as a seizure occurring within 24 hours of CPB, without neurologic deficit or new lesion on brain imaging. Independent determinants of early seizure were examined by multivariate logistic regression modelling.nnnRESULTSnBetween 2004 and 2009, early seizure occurred in 119 of 8,929 patients (1.3%). A significant increase in the yearly rate of early seizure was observed in 2004 (0.73%) vs 2009 (1.97%; p<0.0001). Multivariate analysis showed the following variables were independent predictors of early seizure: age older than 75 years (adjusted odds ratio [OR], 2.1; p=0.0001), open heart procedure (OR, 12.0; p<0.0001), preoperative renal failure (OR, 3.2; p<0.0001), peripheral vascular disease (OR, 1.8; p=0.02), and total tranexamic acid dose of 100 mg/kg or more (OR, 2.6; p<0.0001). Risk of seizure was related to tranexamic acid in a dose-dependent fashion, with higher doses associated with increased risk of seizure. The use of CO2 in a subset of patients undergoing open heart procedures did not decrease the incidence of early seizure (4.8% vs 2.5% for no CO2; p=0.27). Postoperative chest tube drainage and blood product use were similar between patients receiving low-dose and high-dose tranexamic acid.nnnCONCLUSIONSnHigh-dose tranexamic acid (≥100 mg/kg) is independently associated with an increased risk of early seizure. Future tranexamic acid trials should assess the blood-conserving effect of tranexamic acid at a lower dosage and specifically monitor for seizure occurrence.

Transcatheter Aortic Valve Implantation in Patients With Severe Aortic Stenosis and Small Aortic Annulus

OBJECTIVESnValve hemodynamics and clinical outcomes among patients with a small aortic annulus who underwent transcatheter aortic valve implantation (TAVI) were examined.nnnBACKGROUNDnThe presence of a small aortic annulus may complicate the surgical management of patients with severe aortic stenosis (AS). TAVI is an alternative to aortic valve replacement (AVR) in high-risk patients, but few data exist on the results of TAVI in patients with a small aortic annulus.nnnMETHODSnBetween 2007 and 2010, 35 patients (mean age 79.2 ± 9.4 years) with severe AS and an aortic annulus diameter <20 mm (mean 18.5 ± 0.9 mm) underwent TAVI with a 23-mm Edwards SAPIEN bioprosthesis (Edwards Lifesciences, Inc., Irvine, California). Echocardiographic parameters and clinical outcomes were assessed prior to discharge and at 6, 12, and 24 months.nnnRESULTSnProcedural success was achieved in 34 patients (97.1%). There was 1 in-hospital death. Peak and mean transaortic gradients decreased from 76.3 ± 33.0 mm Hg and 45.2 ± 20.6 mm Hg at baseline to 21.8 ± 8.4 mm Hg and 11.7 ± 4.8 mm Hg post-procedure, respectively, both p < 0.0001. Mean indexed effective orifice area (IEOA) increased from 0.35 ± 0.10 cm(2)/m(2) at baseline to 0.90 ± 0.18 cm(2)/m(2) post-procedure, p < 0.0001. Severe prosthesis-patient mismatch (IEOA <0.65 cm(2)/m(2)) occurred in 2 patients (5.9%). At a mean follow-up of 14 ± 11 months, gradients remained low and 30 of the 31 remaining survivors were in New York Heart Association functional class I or II.nnnCONCLUSIONSnIn high-risk patients with severe AS and a small aortic annulus, TAVI is associated with good post-procedural valve hemodynamics and clinical outcomes. TAVI may provide a reasonable alternative to conventional AVR in elderly patients with a small aortic annulus.

Long-Term Clinical and Echocardiographic Follow-Up of the Freestyle Stentless Aortic Bioprosthesis

Background— Stentless aortic bioprostheses were designed to provide enhanced hemodynamic performance and potentially greater longevity. The present report describes the outcomes of patients with the Freestyle stentless bioprosthesis followed for ⩽18 years. Methods and Results— Between 1993 and 2011, 430 patients underwent primary aortic valve replacement with a Freestyle bioprosthesis in the subcoronary position. Mean age was 68.2±8.2 years. All of the clinical and echocardiographic data were collected prospectively. Mean overall follow-up was 9.1±4.4 years and was complete in all of the patients. In-hospital mortality was 3.5% (n=15). Overall, 10- and 15-year survival were 60.7% and 35.0%, respectively. Fifty-one patients required reoperation during follow-up, including 27 for structural valve deterioration (SVD). Overall, freedom from reoperation was 91.0% and 75.0% at 10 and 15 years, whereas freedom from reoperation for SVD was 95.9% and 82.3%, respectively. At 10 and 15 years, freedom from reoperation for SVD was 94.0% and 62.6% for patients <60 years of age and 96.3% and 88.4% for patients ≥60 years of age (P=0.002). The median time to explant for SVD was 10.7 years. SVD presented mostly as acute, severe aortic insufficiency attributed to leaflet tear (77.8%). The independent risk factors for reoperation for SVD were age <60 years (P=0.001) and dyslipidemia (P=0.02). Conclusions— Aortic valve replacement with the Freestyle bioprosthesis in a subcoronary position provides good long-term clinical and echocardiographic outcomes for patients >60 years of age. Severe aortic insufficiency with leaflet tear is the major mode of SVD leading to reoperation in these patients.

Clinical Outcomes Following the Ross Procedure in Adults: A 25-Year Longitudinal Study

BACKGROUNDnVery few reports of long-term outcomes of patients who underwent the Ross procedure have beenxa0published.nnnOBJECTIVESnThe authors reviewed their 25-year experience with the Ross procedure with the aim of defining very-long-term survival and factors associated with Ross-related failure.nnnMETHODSnBetween January 1990 and December 2014, the Ross procedure was performed in 310 adults (mean age 40.8 years) at a single institution. All patients were prospectively added to a dedicated cardiac surgery registry. Complete post-operative clinical examination and history were obtained, and transthoracic echocardiography was performed according to a standardized protocol. There was no loss to follow-up. Median follow-up was 15.1 years and up to 25 years.nnnRESULTSnBicuspid aortic valve was diagnosed in 227 patients (73.2%), and the most common indication for surgery was aortic stenosis (nxa0=xa0225 [72.6%]). Freedom from any Ross-related reintervention was 92.9% and 70.1% at 10 and 20xa0years, respectively. Independent risk factors for pulmonary autograft degeneration were pre-operative large aortic annulus (hazard ratio: 1.1; pxa0=xa00.01), pre-operative aortic insufficiency (hazard ratio: 2.7; pxa0=xa00.002), and concomitant replacement of the ascending aorta (hazard ratio: 7.7; pxa0=xa00.0003). There were 4 hospital deaths (1.3%), and overall survival at 10 and 20 years was 94.1% and 83.6%, respectively. Long-term survival was not significantly different in patients who required Ross-related reintervention (log-rank pxa0=xa00.70). However, compared with the general population, survival was significantly lower in patients following the Ross procedure when matched on age and sex (pxa0< 0.0001).nnnCONCLUSIONSnThe Ross procedure was associated with excellent long-term valvular outcomes and survival,xa0regardless of the need for reintervention. Adults presenting with aortic insufficiency or a dilated aorticxa0annulus or ascending aorta were at greater risk for reintervention. Unlike previous reports, long-term survivalxa0was lower in Rossxa0patients compared with matched subjects.

Surgical aortic valve replacement outcomes in the transcatheter era.

BACKGROUNDnThe primary objective of this study was to evaluate the influence of transcatheter aortic valve implantation (TAVI) on the characteristics and outcomes of patients undergoing surgical aortic valve replacement (SAVR) in a single high-volume Canadian center.nnnMETHODSnBetween January 2003 and December 2013, 1593 patients underwent isolated SAVR at our institution. The study period was divided into 2 distinct cohorts of patients undergoing SAVR: before (n = 529) and after (n = 1064) the first TAVI procedure in May 2007. We compared the risk profiles and clinical outcomes of the 2 cohorts and assessed the multivariate predictors of in-hospital mortality.nnnRESULTSnThe ratio of isolated SAVR to the total number of cardiac surgery cases per year rose significantly after the introduction of TAVI (7.2% vs 9.1%; P < .0001). There was significantly more diabetes, obesity, recent myocardial infarction, and use of a bioprosthesis among SAVR patients in the post-TAVI era (all P values < .05). In-hospital mortality decreased significantly among SAVR patients following the introduction of TAVI (3.6% vs 1.8%; P = .03). Independent risk factors for in-hospital mortality among the entire study population were SAVR in the pre-TAVI era, baseline creatinine, age, and prosthesis size ≤ 21 mm for the pre-TAVI group only.nnnCONCLUSIONSnThe number of isolated SAVR cases increased following the introduction of TAVI. There was a significant reduction in operative mortality of SAVR in the post-TAVI era despite greater severity of several markers of risk. Patient referrals for TAVI should take into consideration the changing risk profiles and improved results of conventional surgery.

Does the use of a free internal mammary artery graft on the left anterior descending artery compromise long-term survival?†

OBJECTIVES The aim of the study was to determine if there is a long‐term outcomes disadvantage associated with using the internal mammary artery (IMA) as a free graft to the left anterior descending artery (LAD) during coronary artery bypass graft surgery. METHODS Between 1991 and 2014, 21 876 consecutive patients underwent isolated primary coronary artery bypass graft surgery at our institution. Among these, 238 underwent a free IMA (f‐IMA) graft to bypass the LAD. Propensity score matching with bootstrap analysis was performed to produce a cohort of 222 f‐IMA patients matched to 222 patients with in situ IMA grafting to the LAD. Early and long‐term outcomes including survival, readmission for cardiovascular causes and repeat revascularization up to a maximum of 23 years post‐coronary artery bypass graft surgery were compared. Provincial vital statistics and administrative hospital readmission data were used to analyse long‐term outcomes. RESULTS Operative mortality [3.2% f‐IMA vs 1.9% in situ IMA; odds ratio = 1.79, 95% confidence interval (CI) = 0.91‐3.52] and the majority of postoperative adverse events were not significantly different among matched patients. The risk of late death was not significantly different between the 2 matched groups (hazard ratio = 1.14, 95% CI = 0.92‐1.41, P = 0.15). The risk of hospital readmission for cardiovascular reasons was significantly higher in the f‐IMA group (54.5% vs 47.3%, odds ratio = 1.4; 95% CI = 1.10‐1.72), although repeat revascularization (18.4% vs 13.5%; odds ratio = 1.53, 95% CI = 0.96‐2.44) was not significantly different between the matched groups. CONCLUSIONS Late survival and the need for repeat coronary revascularization were not influenced by using the IMA as a free graft to the LAD. However, there is a small but significant increase in the risk of hospital readmission for cardiac reasons.

Transcatheter Aortic Valve Replacement for a Failed Mechanical Aortic Prosthesis

The options for reoperation for a dysfunctional mechanical aortic prosthesis in a small aortic root may be limited for high-risk patients. This report describes a case in which transcatheter aortic valve replacement was used through the open aorta on cardiopulmonary bypass to minimize operative duration and reduce the risk of prosthesis-patient mismatch in a patient who was a Jehovahs Witness with a failed 17-mm mechanical aortic prosthesis.

Ascending Aortic Replacement and Sutureless Valve in a Failed Stentless Aortic Prosthesis: A Bailout Option

Aortic valve replacement with a Perceval sutureless bioprosthesis is a viable rescue option for a failed aortic stentless prosthesis. However, a dilated sinotubular junction and ascending aorta are reported as a contraindication for this technique. We describe an aortic sutureless valve implantation in a patient with a dilated ascending aorta and small aortic root after Dacron graft replacement of the ascending aorta in a failed aortic stentless bioprosthesis.