Shelley Rahman-Haley

Coronary artery bypass surgery with or without mitral valve annuloplasty in moderate functional ischemic mitral regurgitation: final results of the Randomized Ischemic Mitral Evaluation (RIME) trial.

Background—The role of mitral valve repair (MVR) during coronary artery bypass grafting (CABG) in patients with moderate ischemic mitral regurgitation (MR) is uncertain. We conducted a randomized, controlled trial to determine whether repairing the mitral valve during CABG may improve functional capacity and left ventricular reverse remodeling compared with CABG alone. Methods and Results—Seventy-three patients referred for CABG with moderate ischemic MR and an ejection fraction >30% were randomized to receive CABG plus MVR (34 patients) or CABG only (39 patients). The study was stopped early after review of interim data. At 1 year, there was a greater improvement in the primary end point of peak oxygen consumption in the CABG plus MVR group compared with the CABG group (3.3 mL/kg/min versus 0.8 mL/kg/min; P<0.001). There was also a greater improvement in the secondary end points in the CABG plus MVR group compared with the CABG group: left ventricular end-systolic volume index, MR volume, and plasma B-type natriuretic peptide reduction of 22.2 mL/m2, 28.2 mL/beat, and 557.4 pg/mL, respectively versus 4.4 mL/m2 (P=0.002), 9.2 mL/beat (P=0.001), and 394.7 pg/mL (P=0.003), respectively. Operation duration, blood transfusion, intubation duration, and hospital stay duration were greater in the CABG plus MVR group. Deaths at 30 days and 1 year were similar in both groups: 3% and 9%, respectively in the CABG plus MVR group, versus 3% (P=1.00) and 5% (P=0.66), respectively in the CABG group. Conclusions—Adding mitral annuloplasty to CABG in patients with moderate ischemic MR may improve functional capacity, left ventricular reverse remodeling, MR severity, and B-type natriuretic peptide levels, compared with CABG alone. The impact of these benefits on longer term clinical outcomes remains to be defined. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00413998.

Towards comprehensive assessment of mitral regurgitation using cardiovascular magnetic resonance.

Cardiovascular magnetic resonance (CMR) is increasingly used to assess patients with mitral regurgitation. Its advantages include quantitative determination of ventricular volumes and function and the mitral regurgitant fraction, and in ischemic mitral regurgitation, regional myocardial function and viability. In addition to these, identification of leaflet prolapse or restriction is necessary when valve repair is contemplated. We describe a systematic approach to the evaluation of mitral regurgitation using CMR which we have used in 149 patients with varying etiologies and severity of regurgitation over a 15 month period.Following standard ventricular cine acquisitions, including 2, 3 and 4 chamber long axis views and a short axis stack for biventricular function, we image movements of all parts of the mitral leaflets using a contiguous stack of oblique long axis cines aligned orthogonal to the central part of the line of coaptation. The 8–10 slices in the stack, orientated approximately parallel to a 3-chamber view, are acquired sequentially from the superior (antero-lateral) mitral commissure to the inferior (postero-medial) commissure, visualising each apposing pair of anterior and posterior leaflet scallops in turn (A1-P1, A2-P2 and A3-P3). We use balanced steady state free precession imaging at 1.5 Tesla, slice thickness 5 mm, with no inter-slice gaps. Where the para-commissural coaptation lines curve relative to the central region, two further oblique cines are acquired orthogonal to the line of coaptation adjacent to each commissure. To quantify mitral regurgitation, we use phase contrast velocity mapping to measure aortic outflow, subtracting this from the left ventricular stroke volume to calculate the mitral regurgitant volume which, when divided by the left ventricular stroke volume, gives the mitral regurgitant fraction. In patients with ischemic mitral regurgitation, we further assess regional left ventricular function and, with late gadolinium enhancement, myocardial viability.Comprehensive assessment of mitral regurgitation using CMR is feasible and enables determination of mitral regurgitation severity, associated leaflet prolapse or restriction, ventricular function and viability in a single examination and is now routinely performed at our centre. The mitral valve stack of images is particularly useful and easy to acquire.

De Novo Aortic Regurgitation After Continuous-Flow Left Ventricular Assist Device Implantation

BACKGROUND Significant aortic regurgitation (AR) after continuous-flow left ventricular assist device (cf-LVAD) placement affects device performance and patient outcomes. This study examined the development of AR and long-term results after implantation of cf-LVADs. METHODS The study included all patients with no or less than mild AR who underwent HeartMate II (58 [62%]; Thoratec Corp, Pleasanton, CA) or HeartWare (35 [38%]; HeartWare International, Framingham, MA) implantation at our institute from July 2006 to July 2012. Serial echocardiograms were obtained preoperatively, at 1, 3 and 6 months postoperatively, and then at a minimum of 4-month intervals in patients with longer-term support. Kaplan-Meier estimates for freedom from moderate or greater AR were generated. Logistic regression analysis was used to define independent predictors of AR after cf-LVAD implantation. RESULTS Median duration of LVAD support was 527 days (25(th), 75(th): 289, 907; range, 60 to 2,433 days). Mild AR developed in 48 patients (51.6%) over a median duration of 126 days, with progression to moderate AR in 13 (14%) over 493 days and to severe AR in 2 (2.1%) over 1,231 days. The incidence of mild or greater AR was 43.1% in HeartMate II vs 65.7% in HeartWare recipients (p = 0.035). Overall freedom from moderate or greater AR was 94.7% ± 2.6% at 1 year, 86.9% ± 4.5% at 2 years, 82.8% ± 5.9% at 3 years, and 31% ± 16.9% at 4 years. Independent predictors of AR were duration of support (odds ratio, 1.002; 95% confidence interval, 1.000 to 1.004; p = 0.017) and a persistently closed aortic valve (odds ratio, 0.193; 95% confidence interval, 0.097 to 0.382; p < 0.001). CONCLUSIONS AR is associated with longer cf-LVAD support duration and persistent aortic valve closure. Incidence of moderate or greater AR after cf-LVAD implantation increases significantly after 3 years. The clinical implications of these data may warrant consideration of prophylactic aortic valve replacement at the time of cf-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AR that is more than mild.

Truly stentless autologous pericardial aortic valve replacement: an alternative to standard aortic valve replacement.

OBJECTIVE The aim of this study was to determine the feasibility and durability of truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall. METHODS Eleven patients (mean age, 55.9 years) requiring aortic valve replacement were recruited. A circular piece of pericardium about 8 cm in diameter was harvested and treated in 0.6% glutaraldehyde for 10 minutes. The aortic valve was excised and, with the use of specially designed instruments (CardioMend LLC, Santa Barbara, Calif), the sinotubular junction was sized and the pericardium was tailored to the required size and shape and then sutured directly onto the aortic wall. The reconstructed valve was assessed directly and by echocardiography at the end of the operation; it was assessed by echocardiography and cardiac magnetic resonance imaging at 6 months and yearly. Computed tomographic scan of the aortic valve to assess for valve calcification was performed at last follow-up. RESULTS Hospital mortality was 0%. Mean follow-up was 6.5 years (range, 5.3-7.5 years). Freedom from structural valve deterioration, thromboembolism, endocarditis and reoperation was 100%, 100%, 72.7%, and 63.6%, respectively. There were 4 reoperations at 4, 13, 15, and 46 months, 3 of them owing to endocarditis and 1 owing to technical failure noted at the time of surgery. The remaining 7 patients are alive and well with a mean New York Heart Association class of 1.3 and normally functioning aortic valves with no calcification. CONCLUSIONS Truly stentless aortic valve replacement using autologous pericardium sutured directly onto the aortic wall is safe and feasible and has excellent durability up to 7.5 years with no calcification.

Does postoperative blood pressure influence development of aortic regurgitation following continuous-flow left ventricular assist device implantation?

OBJECTIVES The true impact of postoperative blood pressure (BP) control on development of aortic regurgitation (AR) following continuous-flow left ventricular assist device (CF-LVAD) implantation remains uncertain. This study examines the influence of BP in patients with de novo AR following CF-LVAD implantation. METHODS All patients with no or <mild AR who underwent CF-LVAD implantation from July 2006 to July 2012 at our institute and with subsequent device-support of ≥3months (n = 90) were studied. Serial echocardiograms and BP readings were obtained preoperatively, postoperatively at 1, 3 and 6 months, and then at a minimum of 4-monthly intervals. BP readings were compared between patients who developed mild AR (AR group) versus those who did not (non-AR group). Logistic regression analysis was used to define independent predictors of ≥mild AR following CF-LVAD implantation. RESULTS Median duration of CF-LVAD support was 575 days (range: 98-2433 days). Forty-eight patients (53.3%) developed mild AR over a median duration of 126 days. BP readings (median values, mmHg) between AR and non-AR groups showed statistically significant differences: at 3 months-systolic 99.5 vs 92.5 (P = 0.038), diastolic 81.5 vs 66 (P < 0.001), mean 86.5 vs 74 (P < 0.001) and at 6 months-diastolic 73 vs 62 (P = 0.044), mean 83 vs 74.5 (P = 0.049), respectively. Systolic BP at 3 months (P = 0.047, 95% CI 0.453-0.994, OR 0.671), aortic valve (AoV) closure (P = 0.01, 95% CI 0.002-0.429, OR 0.029) and duration of support (P = 0.04, 95% CI 1.000-1.009, OR 1.004) were found to be independent predictors of AR following CF-LVAD implantation. CONCLUSIONS BP readings at 3 months and 6 months showed a statistically significant association with ≥mild AR following CF-LVAD implantation, with systolic blood pressure at 3 months, aortic valve closure and longer support duration being independent predictors. Clinical implications of these data may warrant consideration of aggressive early control of BP to protect against the development/progress of AR following CF-LVAD implantation.

Preoperative predictors and outcomes of right ventricular assist device implantation after continuous-flow left ventricular assist device implantation

OBJECTIVE The outcomes of ventricular assist device therapy remain limited by right ventricular failure. We sought to define the predictors and evaluate the outcomes of right ventricular failure requiring right ventricular assist device support after long-term continuous-flow left ventricular assist device implantation. METHODS Records of all continuous-flow left ventricular assist device recipients for the last 10 years were analyzed, including patients on preoperative intra-aortic balloon pump, extracorporeal membrane oxygenation, and short-term ventricular assist device support. Perioperative clinical, echocardiographic, hemodynamic, and laboratory data of continuous-flow left ventricular assist device recipients requiring right ventricular assist device support (right ventricular assist device group) were compared with the rest of the patient cohort (control group). RESULTS Between July 2003 and June 2013, 152 patients underwent continuous-flow left ventricular assist device implantation as a bridge to transplantation. The overall postoperative incidence of right ventricular assist device support was 23.02% (n = 35). Right ventricular assist device implantation did not significantly affect eventual transplantation (P = .784) or longer-term survival (P = .870). Preoperative right ventricular diameter (P < .001), tricuspid annular plane systolic excursion (P < .001), previous sternotomy (P = .002), preoperative short-term mechanical support (P = .005), left atrial diameter (P = .014), female gender (P = .020), age (P = .027), and preoperative bilirubin levels (P = .031) were univariate predictors of right ventricular assist device implantation. Multivariate analysis revealed lesser tricuspid annular plane systolic excursion (P = .013; odds ratio, 0.613; 95% confidence interval, 0.417-0.901) and smaller left atrial diameter (P = .007; odds ratio, 0.818; 95% confidence interval, 0.707-0.947) as independent predictors of right ventricular assist device implantation. Receiver operating characteristic curve of tricuspid annular plane systolic excursion yielded an area under the curve of 0.85 (95% confidence interval, 0.781-0.923), with cutoff tricuspid annular plane systolic excursion less than 12.5 mm having 84% sensitivity and 75% specificity. CONCLUSIONS Lesser tricuspid annular plane systolic excursion and smaller left atrial diameter are independent predictors of the need for right ventricular assist device support after continuous-flow left ventricular assist device implantation. Right ventricular assist device implantation does not adversely affect eventual transplantation or survival after continuous-flow left ventricular assist device implantation.

Coronary Artery Bypass Surgery With or Without Mitral Valve Annuloplasty in Moderate Functional Ischemic Mitral Regurgitation

Background—The role of mitral valve repair (MVR) during coronary artery bypass grafting (CABG) in patients with moderate ischemic mitral regurgitation (MR) is uncertain. We conducted a randomized, controlled trial to determine whether repairing the mitral valve during CABG may improve functional capacity and left ventricular reverse remodeling compared with CABG alone. Methods and Results—Seventy-three patients referred for CABG with moderate ischemic MR and an ejection fraction >30% were randomized to receive CABG plus MVR (34 patients) or CABG only (39 patients). The study was stopped early after review of interim data. At 1 year, there was a greater improvement in the primary end point of peak oxygen consumption in the CABG plus MVR group compared with the CABG group (3.3 mL/kg/min versus 0.8 mL/kg/min; P<0.001). There was also a greater improvement in the secondary end points in the CABG plus MVR group compared with the CABG group: left ventricular end-systolic volume index, MR volume, and plasma B-type natriuretic peptide reduction of 22.2 mL/m2, 28.2 mL/beat, and 557.4 pg/mL, respectively versus 4.4 mL/m2 (P=0.002), 9.2 mL/beat (P=0.001), and 394.7 pg/mL (P=0.003), respectively. Operation duration, blood transfusion, intubation duration, and hospital stay duration were greater in the CABG plus MVR group. Deaths at 30 days and 1 year were similar in both groups: 3% and 9%, respectively in the CABG plus MVR group, versus 3% (P=1.00) and 5% (P=0.66), respectively in the CABG group. Conclusions—Adding mitral annuloplasty to CABG in patients with moderate ischemic MR may improve functional capacity, left ventricular reverse remodeling, MR severity, and B-type natriuretic peptide levels, compared with CABG alone. The impact of these benefits on longer term clinical outcomes remains to be defined. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00413998.

Effect of Aortic Valve Calcium Quantity on Outcome After Balloon Aortic Valvuloplasty for Severe Aortic Stenosis

Balloon aortic valvuloplasty has a role in a select group of patients with severe aortic stenosis. Identifying those appropriate patients who will benefit most is key. Given previous evidence demonstrating that histologically the intervention involves a physical disrupting of the cusps calcium we hypothesized that the quantity of calcium seen at CT will influence outcome. We examined our cohort of patients who had undergone balloon aortic valvuloplasty and CT-quantified aortic valve calcium (AVC) between July 2011 and April 2014. All patients underwent echocardiography pre- and post-procedure and for those patients managed medically, again at 6 months. A potential predictive AVC value for mortality was calculated using Youdens index. A total of 240 aortic valvuloplasties were performed in 206 patients (male = 124). Valvuloplasty caused a significant (pre 0.63 ± 0.21 vs post 0.77 ± 0.27 cm2, p <0.01, n = 240), but temporary (post 0.80 ± 0.27 vs 6 months: 0.64 ± 0.18 cm2, p <0.01, n = 88) increase in valve area. Those patients with a non-severe AVC (<1853.5 AU) had a larger increase in valve area after valvuloplasty compared with those with more calcium (0.10 [95% confidence interval {CI} 0.05 to 0.10] vs 0.15 [95%CI 0.10 to 0.22] cm2, p = 0.049). Multivariate analysis revealed severe AVC (Hazard ratio 2.79, 95% CI 1.18 to 6.63, p = 0.02) along with pulmonary artery pressure post-valvuloplasty (Hazard ratio 1.02, 95% CI 1.00 to 1.03, p = 0.03) to be predictive of survival. In conclusion, in patients with severe aortic stenosis the degree of AVC impacts on the success of valvuloplasty.

Imaging diagnoses and outcome in patients presenting for primary angioplasty but no obstructive coronary artery disease.

Objective A proportion of patients with suspected ST-elevation myocardial infarction (STEMI) presenting for primary percutaneous coronary intervention (PPCI) do not have obstructive coronary disease and other conditions may be responsible for their symptoms and ECG changes. In this study, we set out to determine the prevalence and aetiology of alternative diagnoses in a large PPCI cohort as determined with multimodality imaging and their outcome. Methods From 2009 to 2012, 5238 patients with suspected STEMI were referred for consideration of PPCI. Patients who underwent angiography but had no culprit artery for revascularisation and no previous history of coronary artery disease were included in the study. Troponin values, imaging findings and all-cause mortality were obtained from hospital and national databases. Results A total of 575 (13.0%) patients with a mean age of 58±15 years (69% men) fulfilled the inclusion criteria. A specific diagnosis based on imaging was made in 237 patients (41.2%) including cardiomyopathies (n=104, 18%), myopericarditis (n=48, 8.4%), myocardial infarction/other coronary abnormality (n=27, 4.9%) and severe valve disease (n=23, 4%). Pulmonary embolism and type A aortic dissection were identified in seven (1.2%) and four (0.7%) cases respectively. A total of 40 (7.0%) patients died over a mean follow-up of 42.6 months. Conclusions A variety of cardiac and non-cardiac conditions are prevalent in patients presenting with suspected STEMI but culprit-free angiogram, some of which may have adverse outcomes. Further imaging of such patients could thus be useful to help in appropriate management and follow-up.

35 Right Heart (RH) 2D-Strain Analysis may help to Identify Left Ventricular Assist Device (LVAD) Cadidates at Risk of Developing Postoperative RV Failure

Purpose Right Ventricular Failure (RVF) after LVAD implantation is associated with increased morbidity and mortality. We analyse right (RH) mechanics by 2D echo, strain and haemodynamic indices in an effort to define patters which may predispose to RVF during LVAD support. Methods 70 LV failure patients (47 ± 12 yrs, 59 male, ischaemic: 21%, LV EF: 23%±10) received continuous-flow LVAD as bridge to transplantation within 18 months. Patients were divided into those who developed RVF during LVAD therapy (RVF group) and those who did not (non-RVF). We compared haemodynamic, echo and strain data between the groups. Results 21 patients (30%) developed post-LVAD implantation RVF resulting in lower survival duration (RVF: 372 days ± 345 vs 650 ± 369, p = 0.03), while 14 patients of the RVF group required subsequent right VAD support. There were no significant differences in age, sex, HR or rhythm, LVEF, cardiac index or in RV stroke work index, mean or systolic pulmonary artery pressure, pulmonary vascular resistance index, TAPSE, RV fractional change area, tricuspid regurgitation grade or TDI systolic and diastolic parameters (p > 0.2). However, RVF group had higher RV end-diastolic pressure (RVEDP, 25 ± 7 mmHg vs 15 ± 6, p = 0.02) and higher mean RA pressure (mRAP, 25 ± 6 mmHg vs 15 ± 7, p = 0.03). Additionaly, there was lower RA peak strain (RAPS: 11 ± 1 vs 33 ± 8%, p = 0.01), lower and later-occurring RV global peak strain (RVGS: 8 ± 2.8% vs 9.2 ± 2.5, p = 0.03, time to RVGS: 57% ±10 vs 47 ± 17, p = 0.03), lower and later-occurring RV free wall peak strain (RVFWS: 8.6 ± 2.7% vs 14.8 ± 2.9, p = 0.01, time to RVFWS: 56% ±19 vs 45 ± 17, p = 0.04), lowerRVFW peak systolic strain rate (RVFWSR: 0.94 ± 0.47s-1 vs 1.1 ± 0.3, p = 0.05) occurring earlier in systole (17% ± 10 vs 0.29 ± 0.13, p = 0.04) and higher late RVFW diastolic strain rate (0.43 ± 0,2s-1 vs 0.28 ± 0.21, p = 0.01). RV contraction after PV closure was more frequently seen in the RVF group (30% vs 20%, p = 0.03). There was also greater time delay between RVFW and septal peak strain (RVD, 147 ± 52 ms vs 53 ± 38, p = 0.03) and between RVFWS and LVFWS (136 ± 55 vs 78 ± 40 ms, p = 0.03). LV strain indices were similar for both groups. Independent predictors of RVF were higher mRAP (OR: 6, 95% CI:0.686–0.976, p = 0.03), lower RAPS (OR: 1.2, CI:1.083–1.716, p = 0.003), lower RVFWS (OR: 1.4, CI: 1.012–2.347, p = 0.04) and greater RVD (OR: 1.028, CI:1.008–1.034, p = 0.01). Higher predictive value was shown for RVD (AUC:0.84), mRAP (AUC: 0.82) and RAPS (AUC: 0.795) Conclusion LVAD recipients, who developed post-operative RVF, exhibited lower RAPS and RVFWS and greater RVD, indicating decreased RH compliance and dyssynchronous RV function. RH strain analysis may add incremental value to 2D echo assessment of LVAD candidates and improve decision making before VAD implantation.