Donald Hammer

Nonstress delayed-enhancement magnetic resonance imaging of the myocardium predicts improvement of function after revascularization for chronic ischemic heart disease with left ventricular dysfunction ☆

BACKGROUND The extent of myocardial scarring of the left ventricle (LV) is important in patients with chronic ischemic heart disease (CIHD). With delayed-enhancement magnetic resonance imaging (DE-MRI), scarred myocardium (hyper-enhanced) is easily distinguishable from viable (dark) myocardium. This investigation assessed the use of DE-MRI for predicting functional improvement after coronary artery bypass grafting (CABG) in patients with CIHD and significant LV dysfunction. METHODS The patient population (n = 29) with CIHD and LV dysfunction (ejection fraction 28% +/- 10%) underwent both DE-MRI, to delineate scarred regions before revascularization, and echocardiography (Echo), to assess segmental function before and after CABG (interval 188 +/- 57 days). Using a 16-segment model, LV myocardium was semiquantitatively analyzed for scarring based on DE-MRI and for improvements in resting function by pre- and post-CABG Echo. RESULTS Before CABG, 82% of targeted myocardial segments had abnormal contraction; 78% showed scarring, including 38% with greater than mild amounts (25%-100%). Normal contraction was found in 18% of segments before revascularization; scarred areas were identified in 42%, 84% of which had, at most, minimal amounts (0%-24%). Of segments with pre-CABG dysfunction, 82% with no evidence of scar recovered, compared to only 18% with > or =50% scarring. Amount of hyper-enhancement was a very good indicator of improvement of function, especially at the > or =50%/segment threshold; overall accuracy was 0.74 (95% CI 0.66-0.82, P <.001). CONCLUSIONS In patients with CIHD and significant LV dysfunction, DE-MRI can predict likelihood of functional improvement after revascularization.

Bicuspid aortic valve surgery with proactive ascending aorta repair.

OBJECTIVES Bicuspid aortic valves are associated with aortic catastrophes, particularly dissection. We examined whether proactive repair of associated dilatation would reduce risk of subsequent aortic dissection or reoperation and whether more aggressive resection is needed in patients undergoing bicuspid aortic valve surgery alone. METHODS From January 1993 to June 2003, 1989 patients (of our total experience of 4316) underwent bicuspid aortic valve surgery. Long-term outcomes of 1810 were analyzed according to aortic size and whether bicuspid aortic valve surgery was performed alone or with aortic repair. RESULTS In-hospital 30-day survival was similar (98.8% valve alone vs 98.9% with aortic repair), with no penalty incurred for concomitant aortic repair. Bicuspid aortic valve-alone patients had worse late survival (75% vs 85% at 10 years, P = .0001), but in the matched cohort survival was nearly identical (85% vs 86%; P = .7). With this strategy, freedom from late aortic events was high in both groups (99% valve alone vs 97% with aortic repair at 10 years; P[log-rank] = .06) and similar in the matched cohort (95% vs 97%; P = .2). Approximately 95% of patients undergoing valve-alone surgery had aortic diameters smaller than 4.6 cm or cross-sectional area/height ratios less than 9.4 cm(2)/m; 80% undergoing valve surgery plus aortic repair had diameters larger than 4.1 cm or ratios greater than 7.3 cm(2)/m. Only 0.2% of events occurred at an aortic diameter size of less than 4.5 cm. CONCLUSIONS Aortic size larger than 4.5 cm or aortic cross-sectional area/height ratio greater than 8 to 10 should be considered triggers for concurrent aortic repair, because there is no added risk, and late survival is better; however, more aggressive resection is unwarranted.

Comparison of effectiveness of carvedilol versus metoprolol or atenolol for atrial fibrillation appearing after coronary artery bypass grafting or cardiac valve operation

A retrospective review of 115 patients who underwent cardiac surgery demonstrated a marked reduction in postoperative atrial fibrillation (8% vs 32%, p <0.05) in patients who received carvedilol versus metoprolol or atenolol immediately after surgery. A prospective study examining the possibility of carvedilols greater efficacy in preventing postoperative atrial fibrillation appears warranted.

Extent of Thoracic Aortic Atheroma Burden and Long-Term Mortality After Cardiothoracic Surgery : A Computed Tomography Study

OBJECTIVES We hypothesized that the extent of aortic atheroma of the entire thoracic aorta, determined by pre-operative multidetector-row computed tomographic angiography (MDCTA), is associated with long-term mortality following nonaortic cardiothoracic surgery. BACKGROUND In patients evaluated for cardiothoracic surgery, presence of severe aortic atheroma is associated with adverse short- and long-term post-operative outcome. However, the relationship between aortic plaque burden and mortality remains unknown. METHODS We reviewed clinical and imaging data from all patients who underwent electrocardiographic-gated contrast-enhanced MDCTA prior to coronary bypass or valvular heart surgery at our institution between 2002 and 2008. MDCTA studies were analyzed for thickness and circumferential extent of aortic atheroma in 5 segments of the thoracic aorta. A semiquantitative total plaque-burden score (TPBS) was calculated by assigning a score of 1 to 3 to plaque thickness and to circumferential plaque extent. When combined, this resulted in a score of 0 to 6 for each of the 5 segments and, hence, an overall score from 0 to 30. The primary end point was all-cause mortality during long-term follow-up. RESULTS A total of 862 patients (71% men, 67.8 years) were included and followed over a mean period of 25 ± 16 months. The mean TPBS was 8.6 (SD: ±6.0). The TPBS was a statistically significant predictor of mortality (p < 0.0001) while controlling for baseline demographics, cardiovascular risk factors, and type of surgery including reoperative status. The estimated hazard ratio for TPBS was 1.08 (95% confidence interval: 1.045 to 1.12). Other independent predictors of mortality were glomerular filtration rate (p = 0.015), type of surgery (p = 0.007), and peripheral artery disease (p = 0.03). CONCLUSIONS Extent of thoracic aortic atheroma burden is independently associated with increased long-term mortality in patients following cardiothoracic surgery. Although our data do not provide definitive evidence, they suggest a relationship to the systemic atherosclerotic disease process and, therefore, have important implications for secondary prevention in post-operative rehabilitation programs.

Long-term durability of bicuspid aortic valve repair.

BACKGROUND Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation, occurring in 1% to 2% of the population. Eventually, 20% develop clinically important valvar regurgitation requiring surgical intervention. Aortic valve repair avoids anticoagulation and prosthetic valve-related complications. This study evaluated long-term durability of BAV repair. METHODS From 1985 to 2011, 728 patients, mean age 42±12 years, underwent BAV repair at Cleveland Clinic. Mean follow-up was 9.0±6.2 years (median, 8.3). Factors associated with repair durability (expressed as aortic valve reoperations and echocardiographically estimated gradients and regurgitation) and survival were identified. RESULTS Hospital mortality was 0.41% (n=3), and stroke occurred in 0.27% (n=2). Freedom from aortic valve reoperation at 10 years was 78%. Risk of reoperation was highest immediately after operation and fell rapidly to approximately 2.6%/year up to 15 years. Primary reasons for reoperation were cusp prolapse (38%), aortic stenosis or regurgitation (17%), and aortic regurgitation from root aneurysm (15%). Aortic valve gradients showed an early initial peak, rapidly declined, then rose steadily, accompanied by an increase in left ventricular mass. Survival was 94% at 10 years. A risk factor for early death was greater preoperative mitral valve regurgitation, and for late death, older age at operation, more severe symptoms, and poorer left ventricular function. CONCLUSIONS BAV repair is safe and durable with low mortality, low prevalence of reoperation, and good long-term survival. Cusp prolapse from technical errors and natural progression of disease are the most common causes for reoperation, but progressive natural increase in valve gradient accounts for a substantial proportion as well.

Aortic Dissection in Patients With Bicuspid Aortic Valve-Associated Aneurysms.

BACKGROUND Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging. METHODS From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention. RESULTS Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm--from 4.1% to 13% at 7.2 cm--and then increased steeply at an ascending aortic diameter of 5.3 cm--from 3.8% to 35% at 8.4 cm--corresponding to a cross-sectional area to height ratio of 10 cm(2)/m for sinuses of Valsalva and 13 cm(2)/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73). CONCLUSIONS Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm(2)/m.

Long-term survival, valve durability, and reoperation for 4 aortic root procedures combined with ascending aorta replacement

OBJECTIVE To evaluate long-term results of aortic root procedures combined with ascending aorta replacement for aneurysms, using 4 surgical strategies. METHODS From January 1995 to January 2011, 957 patients underwent 1 of 4 aortic root procedures: valve preservation (remodeling or modified reimplantation, n = 261); composite biologic graft (n = 297); composite mechanical graft (n = 156); or allograft root (n = 243). RESULTS Seven deaths occurred (0.73%), none after valve-preserving procedures, and 13 strokes (1.4%). Composite grafts exhibited higher gradients than allografts or valve preservation, but the latter 2 exhibited more aortic regurgitation (2.7% biologic and 0% mechanical composite grafts vs 24% valve-preserving and 19% allografts at 10 years). Within 2 to 5 years, valve preservation exhibited the least left ventricular hypertrophy, allograft replacement the greatest; however, valve preservation had the highest early risk of reoperation, allograft replacement the lowest. Patients receiving allografts had the highest risk of late reoperation (P < .05), and those receiving composite mechanical grafts and valve preservation had the lowest. Composite bioprosthesis patients had the highest risk of late death (57% at 15 years vs 14%-26% for the remaining procedures, P < .0001), because they were substantially older and had more comorbidities (P < .0001). CONCLUSIONS These 4 aortic root procedures, combined with ascending aorta replacement, provide excellent survival and good durability. Valve-preserving and allograft procedures have the lowest gradients and best ventricular remodeling, but they have more late regurgitation, and likely, less risk of valve-related complications, such as bleeding, hemorrhage, and endocarditis. Despite the early risk of reoperation, we recommend valve-preserving procedures for young patients when possible. Composite bioprostheses are preferable for the elderly.

Midterm Results of David Reimplantation in Patients With Connective Tissue Disorder

BACKGROUND Few series have examined follow-up risks of the David reimplantation operation in patients with connective tissue disorder. Hence, we assessed its midterm safety and effectiveness for Marfan syndrome and other connective tissue disorders, such as Ehlers-Danlos, Loeys-Dietz, and marfanoid syndromes. METHODS Of 313 patients who underwent modified David reimplantation, 178 identified as having connective tissue disorders underwent operation from January 1, 1991, to December 31, 2010. These disorders included Marfan (84%), marfanoid (8.4%), Loeys-Dietz (5.6%), Ehlers-Danlos (1.1%), and other syndromes (1.1%). Concomitant procedures included mitral valve repair in 7.3% and an atrial fibrillation procedure in 3.4%. RESULTS There were no operative or 30-day deaths. Complications included prolonged ventilation (3%), renal failure (3%), reoperation for bleeding (2.2%), and permanent stroke (0.56%). Eight-year survival was 94% and freedom from aortic valve reoperation at 6 years was 92%. Of the 7 aortic valve reoperations, 3 were attributable to endocarditis and 3 to technical failure. One reoperation was performed at another hospital, and the reason could not be determined. There were no late strokes or hemorrhagic events. At 4 years, approximately 70% of patients had no aortic valve regurgitation, and 18% were in grade 1+. CONCLUSIONS Prophylactic root and valve preservation using David reimplantation is safe and provides excellent midterm effectiveness and low risk of late events except for endocarditis.

Aortic Cross-Sectional Area/Height Ratio and Outcomes in Patients with a Trileaflet Aortic Valve and a Dilated Aorta

Background: In patients with a dilated proximal ascending aorta and trileaflet aortic valve, we aimed to assess (1) factors independently associated with increased long-term mortality and (2) the incremental prognostic utility of indexing aortic root to patient height. Methods: We studied consecutive patients with a dilated aortic root (≥4 cm) that underwent echocardiography and gated contrast-enhanced thoracic aortic computed tomography or magnetic resonance angiography between 2003 and 2007. A ratio of aortic root area over height was calculated (cm2/m) on tomography, and a cutoff of 10 cm2/m was chosen as abnormal, on the basis of previous reports. All-cause death was recorded. Results: The cohort comprised 771 patients (63 years [interquartile range, 53–71], 87% men, 85% hypertension, 51% hyperlipidemia, 56% smokers). Inherited aortopathies, moderate to severe aortic regurgitation, and severe aortic stenosis were seen in 7%, 18%, and 2%, whereas 91% and 54% were on &bgr;-blockers and angiotensin-converting enzyme inhibitors, respectively. Aortic root area/height ratio was ≥10 cm2/m in 24%. The Society of Thoracic Surgeons score and right ventricular systolic pressure were 3.3±3 and 31±7 mm Hg, respectively. At 7.8 years (interquartile range, 6.6–8.9), 280 (36%) patients underwent aortic surgery (76% within 1 year) and 130 (17%) died (1% in-hospital postoperative mortality). A lower proportion of patients in the surgical (versus nonsurgical) group died (13% versus 19%, P<0.01). On multivariable Cox proportional hazard analysis, aortic root area/height ratio (hazard ratio, 4.04; 95% confidence interval [CI], 2.69–6.231) was associated with death, whereas aortic surgery (hazard ratio, 0.47; 95% CI, 0.27–0.81) was associated with improved survival (both P<0.01). For longer-term mortality, the addition of aortic root area/height ratio ≥10 cm2/m to a clinical model (Society of Thoracic Surgeons score, inherited aortopathies, hypertension, hyperlipidemia, medications, aortic regurgitation, and right ventricular systolic pressure), increased the c-statistic from 0.57 (95% CI, 0.35–0.77) to 0.65 (95% CI, 0.52–0.73) and net reclassification index from 0.17 (95% CI, 0.02–0.31) to 0.23 (95% CI, 0.04–0.34), both P<0.01. Of the 327 patients with aortic root diameter between 4.5 and 5.5 cm, 44% had an abnormal aortic root area/height ratio, of which 78% died. Conclusions: In patients with dilated aortic root and trileaflet aortic valve, a ratio of aortic root area to height provides independent and improved stratification for prediction of death.

First-in-Human Implantations of the NaviGate Bioprosthesis in a Severely Dilated Tricuspid Annulus and in a Failed Tricuspid Annuloplasty Ring

Based on an old misconception that the tricuspid valve is not important for cardiac performance, functional tricuspid regurgitation (TR) has been historically ignored. As a consequence, an increasing number of patients present in the current era with severe TR associated with right heart failure that is refractory to medical treatment. Traditional or redotricuspid valve surgery in that setting has been shown to have high mortality (up to 35% at 30 days).1–3 Thereby, transcatheter valve implantation technology seems as an attractive alternative. Herein, we report the first-in-human successful implantation of the NaviGate valved-stent (NaviGate Cardiac Structures, Inc, NCSI, Lake Forest, CA) in 2 patients with severe TR and prohibitive risk for conventional surgery, for which they received Food and Drug Administration and institutional review board approvals for compassionate use (Figure 1). Figure 1. The NaviGate valved-stent. A , Ventricular view. B , Lateral view. A 64-year-old woman presented after multiple admissions for refractory right heart failure with severe functional TR secondary to annular dilatation, severe right ventricular (RV) dysfunction, severe pulmonary hypertension (systolic pressure, 75 mm Hg), and moderate ischemic mitral regurgitation (Figure 2A). Other comorbidities included chronic kidney dysfunction, chest radiation for breast cancer, atrial fibrillation, obstructive lung disease, and coronary bypass surgery with patent grafts. The patient was deemed high risk for conventional open-heart surgery by the Multidisciplinary Heart Team and was found a candidate for compassionate use of a first-in-human NaviGate valved-stent implantation. Preoperative sizing included a focused 4-dimensional computed tomography that was used to develop a 3-dimensional printing model of the …