Faculty Bibliography

Limited evidence exists to guide the use of early parenteral anticoagulation following mechanical heart valve replacement (MVR). The purpose of this study was to compare the 30-day rates of thrombotic and bleeding complications for MVR patients receiving therapeutic versus prophylactic dose bridging regimens. In this retrospective cohort study we reviewed anticoagulation management and outcomes of all patients undergoing MVR at five Canadian hospitals between 2003 and 2010. The primary efficacy outcome was thromboembolism (stroke, transient ischaemic attack, systemic embolism or valve thrombosis) and the primary safety outcome was major bleeding at 30-days. Outcomes were compared using a logistic regression model adjusting for propensity score and in a 1:1 propensity matched sample. A total of 1777 patients underwent mechanical valve replacement, of whom 923 received therapeutic dose bridging anticoagulation and 764 received prophylactic dose bridging postoperatively. Sixteen patients (1.8 %) who received therapeutic dose bridging and fifteen patients (2.1 %) who received prophylactic dose bridging experienced the primary efficacy outcome (odds ratio [OR] 0.90; 95 % confidence interval [CI], 0.37 to 2.18, p=0.81). Forty-eight patients (5.4 %) in the therapeutic dosing group and 14 patients (1.9 %) in the prophylactic dosing group experienced the primary safety outcome of major bleeding (OR 3.23; 95 % CI, 1.58 to 6.62; p=0.001). The direction of the effects, their magnitude and significance were maintained in the propensity matched analysis. In conclusion, we found that early after mechanical valve replacement, therapeutic dose bridging was associated with a similar risk of thromboembolic complications, but a 2.5 to 3-fold increased risk of major bleeding compared with prophylactic dose bridging.

OBJECTIVE:To demonstrate a novel, reproducible, and effective method of direct innominate artery cannulation using a 14 F pediatric venous cannula to establish antegrade cerebral protection (ACP) in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. METHODS:We reviewed prospectively gathered data on all patients who had undergone replacement of the ascending aorta or hemiarch with an open distal anastomosis using deep hypothermic circulatory arrest and direct innominate artery cannulation with a 14 F pediatric venous cannula at our institution. After central cannulation and cooling to 25 °C to 28 °C, all patients had ACP initiated by way of a direct innominate cannula placed over a guidewire. RESULTS:Fifty patients underwent direct innominate artery cannulation with our technique from 2010 to 2012. The operative mortality was 2% (n = 1), and the rates of neurologic morbidity were acceptable and similar to those with other methods of ACP delivery: stroke (2%, n = 1), seizure (0%, n = 0), and delirium (18%, n = 9). The mean operative time was 31 ± 9, 19 ± 5, 100 ± 39, 141 ± 39, and 259 ± 63 minutes for cooling, circulatory arrest, crossclamp, cardiopulmonary bypass, and total operative time, respectively. No local or arterial complications were observed. CONCLUSIONS:Direct cannulation of the innominate artery using a 14 F pediatric venous cannula is a simple, reproducible, safe, and effective technique for establishing ACP in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. This technique avoids the additional time and potential local complications associated with other established methods for delivering ACP, such as axillary cannulation.

BACKGROUND:There is increasing demand for transcatheter aortic valve replacement (TAVR) as the primary treatment option for patients with severe aortic stenosis who are high-risk surgical candidates or inoperable. We used mathematical simulation models to estimate the hypothetical effectiveness of TAVR with increasing wait times. METHODS:We applied discrete event modelling, using data from the Placement of Aortic Transcatheter Valves (PARTNER) trials. We compared TAVR with medical therapy in the inoperable cohort, and compared TAVR to conventional aortic valve surgery in the high-risk cohort. One-year mortality and wait-time deaths were calculated in different scenarios by varying TAVR wait times from 10 days to 180 days, while maintaining a constant wait time for surgery at a mean of 15.6 days. RESULTS:In the inoperable cohort, the 1-year mortality for medical therapy was 50%. When the TAVR wait time was 10 days, the TAVR wait-time mortality was 1.9% with a 1-year mortality of 31.5%. TAVR wait-time deaths increased to 28.9% with a 180-day wait, with a 1-year mortality of 41.4%. In the high-risk cohort, the wait-time deaths and 1-year mortality for the surgical patients were 2.5% and 27%, respectively. The TAVR wait-time deaths increased from 2.2% with a 10-day wait to 22.4% with a 180-day wait, and a corresponding increase in 1-year mortality from 24.5% to 32.6%. Mortality with TAVR exceeded surgery when TAVR wait times exceeded 60 days. CONCLUSIONS:Modest increases in TAVR wait times have a substantial effect on the effectiveness of TAVR in inoperable patients and high-risk surgical candidates.

Transcatheter aortic valve implantation (TAVI) has demonstrated the feasibility of treating valvular heart disease with transcatheter therapy. On the back of this success, various transcatheter concepts are being evaluated to treat other valvular disease, especially mitral regurgitation (MR). The concepts currently approved to treat MR replicate surgical mitral valve repair. However, most of them cannot eliminate MR completely. Similar to TAVI, a transcatheter mitral valve implantation may provide a valuable alternative. The FORTIS transcatheter mitral valve (Edwards Lifesciences, Irvine, CA, USA) is a self-expanding device implanted via a transapical approach. We describe our experience and early results in the first five patients treated on compassionate grounds. We also describe the details of the device, selection criteria and technical details of implantation.

In this report we present a 43-year-old male with achondroplastic dwarfism who presented with acute Type A aortic dissection with aortic insufficiency. The patient underwent successful Bentall and hemiarch repair. Anesthetic, perfusion-related, and surgical planning and execution are presented.

Little is known about the relation between type A acute aortic dissection (TAAAD) and pulse pressure (PP), defined as the difference between systolic and diastolic blood pressure. In this study, we explored the association between PP and presentation, complications, and outcomes of patients with TAAAD. PP at hospital presentation was used to divide 1,960 patients with noniatrogenic TAAAD into quartiles: narrowed (≤39 mm Hg, n=430), normal (40 to 56 mm Hg, n=554), mildly elevated (57 to 75 mm Hg, n=490), and markedly elevated (≥76 mm Hg, n=486). Variables relating to index presentation and in-hospital outcomes were analyzed. Patients with TAAAD in the narrowed PP quartiles were frequently older and Caucasian, whereas patients with markedly elevated PPs tended to be male and have a history of hypertension. Patients who demonstrated abdominal vessel involvement more commonly demonstrated elevated PPs, whereas patients with narrowed PPs were more likely to have periaortic hematoma and/or pericardial effusion. Narrowed PPs were also correlated with greater incidences of hypotension, cardiac tamponade, and mortality. Patients with TAAAD who were managed with endovascular and hybrid procedures and those with renal failure tended to have markedly elevated PPs. No difference in aortic regurgitation at presentation was noted among groups. In conclusion, patients with TAAAD in the third PP quartile had better in-hospital outcomes than patients in the lowest quartile. Patients with narrowed PPs experienced more cardiac complications, particularly cardiac tamponade, whereas those with markedly elevated PPs were more likely to have abdominal aortic involvement. Presenting PP offers a clue to different manifestations of acute aortic dissection that may facilitate initial triage and care.

OBJECTIVES/OBJECTIVE:The aim of this study was to determine the impact of new-onset persistent left bundle branch block (NOP-LBBB) on late outcomes after transcatheter aortic valve implantation (TAVI). BACKGROUND:The impact of NOP-LBBB after TAVI remains controversial. METHODS:A total of 668 consecutive patients who underwent TAVI with a balloon-expandable valve without pre-existing LBBB or permanent pacemaker implantation (PPI) were included. Electrocardiograms were obtained at baseline, immediately after the procedure, and daily until hospital discharge. Patients were followed at 1, 6, and 12 months and yearly thereafter. RESULTS:New-onset LBBB occurred in 128 patients (19.2%) immediately after TAVI and persisted at hospital discharge in 79 patients (11.8%). At a median follow-up of 13 months (range 3 to 27 months), there were no differences in mortality rate between the NOP-LBBB and no NOP-LBBB groups (27.8% vs. 28.4%; adjusted-hazard ratio: 0.87 [95% confidence interval (CI): 0.55 to 1.37]; p = 0.54). There were no differences between groups regarding cardiovascular mortality (p = 0.82), sudden death (p = 0.87), rehospitalizations for all causes (p = 0.11), or heart failure (p = 0.55). NOP-LBBB was the only factor associated with an increased rate of PPI during the follow-up period (13.9% vs. 3.0%; hazard ratio: 4.29 [95% CI: 2.03 to 9.07], p < 0.001. NOP-LBBB was also associated with a lack of left ventricular ejection fraction improvement and poorer New York Heart Association functional class at follow-up (p < 0.02 for both). CONCLUSIONS:NOP-LBBB occurred in ∼1 of 10 patients who had undergone TAVI with a balloon-expandable valve. NOP-LBBB was associated with a higher rate of PPI, a lack of improvement in left ventricular ejection fraction, and a poorer functional status, but did not increase the risk of global or cardiovascular mortality or rehospitalizations at 1-year follow-up.

BACKGROUND: Complicated acute type B aortic dissection (cABAD) generally requires urgent intervention. Advanced age is a risk factor for mortality after thoracic aortic intervention, including surgery for aortic dissection. The purpose of this study was to investigate the exact impact of increasing age on the management and outcomes of cABAD. METHODS: We analyzed the outcomes of 583 patients with cABAD enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2012. All patients with cABAD were categorized according to age by decade and management type (medical, surgical, or endovascular treatment), and outcomes were subsequently investigated in the different age groups. RESULTS: The mean age of the cohort was 63.4 +/- 14.2 years, 36% of patients (n = 209) were greater than 70 years of age and 64% (n = 374) were less than 70 years. The utilization of surgery and endovascular techniques progressively decreased with patient age, while the rate of medical management significantly increased with age (p < 0.001). The in-hospital mortality rates for complicated patients younger than 70 years versus 70 years or more were 10.1% versus 30.0% for endovascular treatment (p = 0.001), 17.2% versus 34.2% for surgical treatment (p = 0.027), and 14.2% versus 32.2% for medical treatment (p = 0.001). Age 70 years or greater was a predictor of in-hospital mortality in multivariate analysis (odds ratio 2.37, 95% confidence interval: 1.23 to 4.54, p = 0.010). CONCLUSIONS: Advanced age has a dramatic impact on the management and outcomes of patients with cABAD. A nonsignificant trend toward lower mortality after endovascular management was observed, both for younger patients and for elderly patients.

OBJECTIVE:Clinical practice guidelines have been established for surgical management of the aorta in bicuspid aortic valve disease. We hypothesized that surgeons' knowledge of and attitudes toward bicuspid aortic valve aortopathy influence their surgical approaches. METHODS:We surveyed cardiac surgeons to probe the knowledge of, attitudes toward, and surgical management of bicuspid aortopathy. A total of 100 Canadian adult cardiac surgeons participated. RESULTS:Fifty-two percent of surgeons believed that the mechanism underlying aortic dilation in those with bicuspid aortic valve was due to an inherent genetic abnormality of the aorta, whereas only 2% believed that altered valve-related processes were involved in this process. Only a minority (15%) believed that bicuspid valve leaflet fusion type is associated with a unique pattern of aortic dilatation aortic phenotype. Sixty-five percent of surgeons recommended echocardiographic screening of first-degree relatives of patients with bicuspid aortic valve. Most surgeons (61%) elected to replace the aorta when the diameter is 45 mm or greater at the time of valve surgery. Fifty-five percent of surgeons surveyed suggested that in the absence of concomitant valvular disease, they would recommend ascending aortic replacement at a threshold of 50 mm or greater. Approximately one third of surgeons suggested that they would elect to replace a mildly dilated ascending aorta (40 mm) at the time of valve surgery. The most common surgical approach (61%) for combined valve and aortic surgery was aortic valve replacement and supracoronary replacement of the ascending aorta, and only a minority suggested the use of deep hypothermic circulatory arrest and open distal anastomosis. More aggressive approaches were favored with greater surgeon experience, and when circulatory arrest was chosen, the majority (68%) suggested they would use antegrade cerebral perfusion. In the setting of aortic insufficiency and a dilated aorta, 42% of surgeons suggested that they would perform valve-sparing surgery. Of note, 40% of respondents used an index measure of aortic size to body surface area in addition to absolute aortic diameter in assessing the threshold for intervention. CONCLUSIONS:This large survey uncovered significant gaps in the knowledge and attitudes of surgeons toward the diagnosis and management of bicuspid aortopathy, many of which were at odds with current guideline recommendations. Efforts to promote knowledge translation in this area are strongly encouraged.

BACKGROUND:Prior cardiac surgery (PCS) can complicate the presentation and management of patients with type A acute aortic dissection (TAAAD). This report from the International Registry of Acute Aortic Dissection examines this hypothesis. METHODS AND RESULTS/RESULTS:A total of 352 of 2196 patients with TAAAD (16%) enrolled in the International Registry of Acute Aortic Dissection had cardiac surgery before dissection, including coronary artery bypass grafting (34%), aortic or mitral valve surgery (36%), aortic surgery (42%), and other cardiac surgery (16%). Those with PCS were older, had a higher frequency of diabetes mellitus, hypertension, and atherosclerosis, and presented later from symptom onset to hospital presentation and diagnosis (all P<0.05). In-hospital mortality was significantly higher for PCS patients (34% versus 23%; P<0.001). Five-year mortality was independently predicted by PCS (hazard ratio [HR], 2.04; 95% confidence interval [CI], 1.05-3.95), age >70 years (HR, 2.65; 95% CI, 1.40-5.05), medical management (HR, 5.10; 95% CI, 2.43-10.71), distal communication (HR, 2.64; 95% CI, 1.35-5.14), and coma (HR, 9.50; 95% CI, 2.05-44.05). Among patients with PCS, in-hospital (43% medical versus 30% surgical; P=0.033) and intermediate-term mortality was higher in patients with medical versus surgical management. Propensity-matched analysis revealed significant increase in mortality with medical management, but not with PCS. CONCLUSIONS:PCS delays presentation, diagnosis, and treatment of TAAAD and is an important adverse risk factor for early and intermediate-term mortality. This effect may be because of increased medical management in this patient population.