Concomitant cardiac surgery and fixation of bilateral rib fractures sustained during cardiopulmonary resuscitation.

BACKGROUND: Chest compressions during cardiopulmonary resuscitation (CPR) may cause sternal or rib fractures and chest wall instability. This can complicate medical management and significantly impair respiratory function. Surgical management of flail chest is technically demanding, and it becomes even more challenging if the patient requires a concomitant cardiac procedure. CASE PRESENTATION: A 78-year-old male suffered a cardiac arrest and sustained sternal and bilateral rib fractures during a successful CPR. He underwent a concomitant coronary artery bypass grafting and aortic valve replacement combined with stabilization of the chest wall. We discuss the possibility of fixation of bilateral rib fractures and its role in postoperative recovery after cardiac surgery. CONCLUSIONS: Chest wall stabilization for an already fragile patient, with impaired respiratory system performance, could help improve overall outcomes, pulmonary function, weaning from mechanical ventilation, and rehabilitation. It may be used together with a cardiac procedure for a life-threatening cardiac pathology.

The impact of COVID-19 pandemic on aortic valve surgical service: a single centre experience.

BACKGROUND: The coronavirus-disease 2019 (COVID-19) pandemic imposed an unprecedented burden on the provision of cardiac surgical services. The reallocation of workforce and resources necessitated the postponement of elective operations in this cohort of high-risk patients. We investigated the impact of this outbreak on the aortic valve surgery activity at a single two-site centre in the United Kingdom. METHODS: Data were extracted from the local surgical database, including the demographics, clinical characteristics, and outcomes of patients operated on from March 2020 to May 2020 with only one of the two sites resuming operative activity and compared with the respective 2019 period. A similar comparison was conducted with the period between June 2020 and August 2020, when operative activity was restored at both institutional sites. The experience of centres world-wide was invoked to assess the efficiency of our services. RESULTS: There was an initial 38.2% reduction in the total number of operations with a 70% reduction in elective cases, compared with a 159% increase in urgent and emergency operations. The attendant surgical risk was significantly higher [median Euroscore II was 2.7 [1.9-5.2] in 2020 versus 2.1 [0.9-3.7] in 2019 (p = 0.005)] but neither 30-day survival nor freedom from major post-operative complications (re-sternotomy for bleeding/tamponade, transient ischemic attack/stroke, renal replacement therapy) was compromised (p > 0.05 for all comparisons). Recommencement of activity at both institutional sites conferred a surgical volume within 17% of the pre-COVID-19 era. CONCLUSIONS: Our institution managed to offer a considerable volume of aortic valve surgical activity over the first COVID-19 outbreak to a cohort of higher-risk patients, without compromising post-operative outcomes. A backlog of elective cases is expected to develop, the accommodation of which after surgical activity normalisation will be crucial to monitor.

Long-Term Follow-Up of Isolated Epicardial Left Ventricular Lead Implant Using a Minithoracotomy Approach for Cardiac Resynchronization Therapy.

BACKGROUND: Transvenous left ventricular (LV) lead placement for cardiac resynchronization therapy is unsuccessful in 5-10% of reported cases. These patients may benefit from isolated surgical placement of an epicardial LV lead via minithoracotomy approach. AIM: To evaluate the success of this approach at long-term follow-up. METHODS: Retrospective evaluation of all consecutive patients undergoing isolated epicardial LV lead placement after failed transvenous attempt over a 6-year period. Data collected on baseline parameters, procedural details, and outcome at follow-up (hospital stay, complications, mortality, and clinical response). RESULTS: Forty-two patients underwent epicardial lead implant. Five died within 1 year (11.9%): two (4.8%) died within 30-days post op (one from intraoperative hemorrhage, the other from multiple organ failure); 39 (95.1%) were admitted to the high dependency unit and transferred to the ward <24 hours. Median hospital stay was 3.4 ± 1.9 days. The overall complication rate was 17.5% (n = 7): 15.0% (n = 6) short term and 2.5% (n = 1) long term; these included three (7.5%) LV noncapture events all treated with reprogramming. There were two (5.0%) wound infections requiring oral antibiotics and two (5.0%) device infections requiring intravenous antibiotics (one had device resiting, the other developed septic shock requiring intensive care admission). Assessment of clinical response was possible in 34 (81.0%) at follow-up: 21 (61.8%) were responders and 13 (28.2%) nonresponders with no significant differences between these groups; no clinical predictors of response were identified. CONCLUSION: Isolated epicardial LV lead implant using minithoracotomy is relatively safe and effective at successful LV pacing. Response rate and postoperative recovery at long-term follow-up are reasonable in these high-risk patients.

Antiplatelet Resistance in Patients Who Underwent Coronary Artery Bypass Grafting: A Systematic Review and Meta-Analysis.

Antiplatelet therapy (APT) with aspirin and a P2Y12 inhibitor is commonly given to patients who underwent coronary artery bypass grafting (CABG) to reduce thrombotic events. APT resistance, the inadequate antiplatelet effect of these drugs, is a growing concern. This review aimed to assess APT resistance prevalence in patients who underwent CABG and its impact on clinical outcomes. We conducted a comprehensive search for relevant studies published to date. The included studies measured platelet function through laboratory assays and reported on clinical outcomes in patients who underwent CABG. The primary outcomes were major adverse cardiovascular events (MACEs) and mortality, whereas the secondary outcomes included acute coronary syndrome (ACS), stroke, and thromboembolic events. The meta-analysis used random-effects models, with heterogeneity assessed using the I2 statistic. The initial search identified 45 studies, with 11 meeting the inclusion criteria, involving 3,122 patients. The overall prevalence of APT resistance in patients who underwent CABG was 39%. Patients with APT resistance had significantly higher risks of MACEs and death (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.06 to 2.83, p = 0.03) and postoperative myocardial infarction (OR 2.25, 95% CI 1.13 to 4.48, p = 0.02) than those without resistance. However, no significant association was found between APT resistance and stroke (OR 2.25, 95% CI 0.80 to 6.35, p = 0.12) or other thromboembolic events (OR 1.72, 95% CI 0.72 to 4.08, p = 0.22). In conclusion, APT resistance is prevalent in a significant proportion of patients who underwent CABG, increasing the risk of MACEs and postoperative myocardial infarction. These findings emphasize the need for further research to develop tailored antiplatelet strategies in this patient population.

Assessment of left ventricular tissue mitochondrial bioenergetics in patients with stable coronary artery disease.

Recurrent myocardial ischemia can lead to left ventricular (LV) dysfunction in patients with coronary artery disease (CAD). In this observational cohort study, we assessed for chronic metabolomic and transcriptomic adaptations within LV myocardium of patients undergoing coronary artery bypass grafting. During surgery, paired transmural LV biopsies were acquired on the beating heart from regions with and without evidence of inducible ischemia on preoperative stress perfusion cardiovascular magnetic resonance. From 33 patients, 63 biopsies were acquired, compared to analysis of LV samples from 11 donor hearts. The global myocardial adenosine triphosphate (ATP):adenosine diphosphate (ADP) ratio was reduced in patients with CAD as compared to donor LV tissue, with increased expression of oxidative phosphorylation (OXPHOS) genes encoding the electron transport chain complexes across multiple cell types. Paired analyses of biopsies obtained from LV segments with or without inducible ischemia revealed no significant difference in the ATP:ADP ratio, broader metabolic profile or expression of ventricular cardiomyocyte genes implicated in OXPHOS. Differential metabolite analysis suggested dysregulation of several intermediates in patients with reduced LV ejection fraction, including succinate. Overall, our results suggest that viable myocardium in patients with stable CAD has global alterations in bioenergetic and transcriptional profile without large regional differences between areas with or without inducible ischemia.

Temporal onset, risk factors, and outcomes associated with stroke after coronary artery bypass grafting.

CONTEXT: Stroke is a devastating and potentially preventable complication of coronary artery bypass graft (CABG) surgery. Better understanding of the timing and risk factors for stroke associated with CABG are needed. OBJECTIVES: To investigate temporal trends in stroke after CABG and to identify stroke risk factors and association with longitudinal outcomes. DESIGN, SETTING, AND PATIENTS: Prospective study conducted from 1982 through 2009 at a single US academic medical center among 45,432 consecutive patients (mean age, 63 [SD, 10] years) undergoing isolated primary or reoperative CABG surgery. Strokes occurring following CABG were recorded prospectively and classified as having occurred intraoperatively or postoperatively. Complications and survival after stroke were assessed in propensity-matched groups. INTERVENTION: CABG performed using 4 different operative strategies (off-pump, on-pump with beating heart, on-pump with arrested heart, on-pump with hypothermic circulatory arrest). MAIN OUTCOME MEASURES: Hospital complications; late survival. RESULTS: Among 45,432 patients undergoing CABG surgery, 705 (1.6% [95% confidence interval {CI}, 1.4%-1.7%]) experienced a stroke. The prevalence of stroke peaked in 1988 at 2.6% (95% CI, 1.9%-3.4%), then declined at 4.69% (95% CI, 4.68%-4.70%) per year (P = .04), despite increasing patient comorbidity. Overall, 279 strokes (40%) occurred intraoperatively and 409 (58%) occurred postoperatively (timing indeterminate in 17 patients). Postoperative stroke peaked at 40 hours, decreasing to 0.055%/d (95% CI, 0.047%-0.065%) by day 6. Risk factors for both intraoperative and postoperative stroke included older age (odds ratio, 8.5 [95% CI, 3.2-22]) and variables representing arteriosclerotic burden. Intraoperative stroke rates were lowest in off-pump CABG (0.14% [95% CI, 0.029%-0.40%]) and on-pump beating-heart CABG (0% [95% CI, 0%-1.6%]), intermediate with on-pump arrested-heart CABG (0.50% [95% CI, 0.41%-0.61%]), and highest with on-pump CABG with hypothermic circulatory arrest (5.3% [95% CI, 2.0%-11%]). Patients with stroke had worse adjusted hospital outcomes, longer intensive care and postoperative stays, and worse downstream survival (mean, 11 [SD, 8.6] years). CONCLUSION: Among patients undergoing CABG surgery at a single center over the past 30 years, the occurrence of stroke declined despite an increasing patient risk profile, and more than half of strokes occurred postoperatively rather than intraoperatively.

Use of Impella RP for Acute Right Ventricular Failure Post-Pericardiectomy.

Surgical pericardiectomy is the accepted treatment for patients with constrictive pericarditis. Right ventricular failure in patients that undergo pericardiectomy is a frequent complication due to sudden volume overload. Impella RP is used to bypass the right ventricle and tackle the transient right ventricular failure. It is implanted percutaneously and provides enough support to achieve haemodynamical stability and recover end-organ function. We report the case of a patient that developed acute right ventricular failure in the early postoperative period of a pericardiectomy. He underwent the implantation of an Impella RP in the setting of acute right ventricular failure and was successfully explanted after 6 days of support.

Identifying Myocardial Infarction Using Hierarchical Template Matching-Based Myocardial Strain: Algorithm Development and Usability Study.

BACKGROUND: Myocardial infarction (MI; location and extent of infarction) can be determined by late enhancement cardiac magnetic resonance (CMR) imaging, which requires the injection of a potentially harmful gadolinium-based contrast agent (GBCA). Alternatively, emerging research in the area of myocardial strain has shown potential to identify MI using strain values. OBJECTIVE: This study aims to identify the location of MI by developing an applied algorithmic method of circumferential strain (CS) values, which are derived through a novel hierarchical template matching (HTM) method. METHODS: HTM-based CS H-spread from end-diastole to end-systole was used to develop an applied method. Grid-tagging magnetic resonance imaging was used to calculate strain values in the left ventricular (LV) myocardium, followed by the 16-segment American Heart Association model. The data set was used with k-fold cross-validation to estimate the percentage reduction of H-spread among infarcted and noninfarcted LV segments. A total of 43 participants (38 MI and 5 healthy) who underwent CMR imaging were retrospectively selected. Infarcted segments detected by using this method were validated by comparison with late enhancement CMR, and the diagnostic performance of the applied algorithmic method was evaluated with a receiver operating characteristic curve test. RESULTS: The H-spread of the CS was reduced in infarcted segments compared with noninfarcted segments of the LV. The reductions were 30% in basal segments, 30% in midventricular segments, and 20% in apical LV segments. The diagnostic accuracy of detection, using the reported method, was represented by area under the curve values, which were 0.85, 0.82, and 0.87 for basal, midventricular, and apical slices, respectively, demonstrating good agreement with the late-gadolinium enhancement-based detections. CONCLUSIONS: The proposed applied algorithmic method has the potential to accurately identify the location of infarcted LV segments without the administration of late-gadolinium enhancement. Such an approach adds the potential to safely identify MI, potentially reduce patient scanning time, and extend the utility of CMR in patients who are contraindicated for the use of GBCA.

On-pump and off-pump coronary artery bypass grafting for patients needing at least two grafts: comparative outcomes at 20 years.

OBJECTIVES: Despite evidence from several randomized controlled trials and observational studies validating short-term safety and efficacy of off-pump coronary artery bypass grafting (CABG), concerns persist regarding the impact of off-pump CABG on long-term survival and freedom from reintervention. This persistent scepticism regarding off-pump CABG prompted us to review our practice of CABG over the last 20 years with a view to comparing the impact of off-pump and on-pump CABG on short-term and long-term outcomes in a high-volume off-pump coronary surgery centre. METHODS: We retrospectively analysed prospectively collected data from the Patients Analysis and Tracking System database (Dendrite Clinical Systems, Oxford, UK) for all isolated first-time CABG procedures with at least 2 grafts performed at our institution from January 1996 to September 2017. Over the study period, 5995 off-pump CABG and 4875 on-pump CABG were performed by surgeons with exclusive off-pump and on-pump practices, respectively. Multivariable logistic regression and the Cox model were used to investigate the effect of off-pump versus on-pump procedures on short-term outcomes and long-term survival. Propensity score matching was used to compare the 2 matched groups. RESULTS: Off-pump CABG was associated with a lower risk for 30-day mortality [odds ratio (OR) 0.42, 95% confidence interval (CI) 0.32-0.55; P < 0.001], reintubation/tracheostomy (OR 0.58, 95% CI 0.47-0.72; P < 0.001) and re-exploration for bleeding (OR 0.48, 95% CI 0.37-0.62; P < 0.001). The benefit in terms of operative deaths from off-pump was significant in those with Society of Cardio-Thoracic Surgery logistic EuroSCORE >2 (interaction P = 0.04). When compared with on-pump CABG, off-pump CABG did not significantly reduce the risk of stroke (OR 0.96, 95% CI 0.88-1.12; P = 0.20) and postoperative haemofiltration (OR 0.98, 95% CI 0.86-1.20; P = 0.35). At the median follow-up of 12 years (interquartile range 6-17, max 21), off-pump CABG did not affect late survival [log rank P = 0.24; hazard ratio (HR) 0.95, 95% CI 0.89-1.02] or the need for reintervention (log rank P = 0.12; HR 1.19, 95% CI 0.95-1.48). CONCLUSIONS: This large volume, single-centre study with the longest reported follow-up confirms that off-pump CABG performed by experienced surgeons, who perform only off-pump procedures in a high-volume off-pump coronary surgery centre, is associated with lower risk of operative deaths, fewer postoperative complications and similar 20-year survival and freedom from reintervention rates compared with on-pump CABG.

Hierarchical Template Matching for 3D Myocardial Tracking and Cardiac Strain Estimation.

Myocardial tracking and strain estimation can non-invasively assess cardiac functioning using subject-specific MRI. As the left-ventricle does not have a uniform shape and functioning from base to apex, the development of 3D MRI has provided opportunities for simultaneous 3D tracking, and 3D strain estimation. We have extended a Local Weighted Mean (LWM) transformation function for 3D, and incorporated in a Hierarchical Template Matching model to solve 3D myocardial tracking and strain estimation problem. The LWM does not need to solve a large system of equations, provides smooth displacement of myocardial points, and adapt local geometric differences in images. Hence, 3D myocardial tracking can be performed with 1.49 mm median error, and without large error outliers. The maximum error of tracking is up to 24% reduced compared to benchmark methods. Moreover, the estimated strain can be insightful to improve 3D imaging protocols, and the computer code of LWM could also be useful for geo-spatial and manufacturing image analysis researchers.

In vivo estimation of passive biomechanical properties of human myocardium.

Identification of in vivo passive biomechanical properties of healthy human myocardium from regular clinical data is essential for subject-specific modelling of left ventricle (LV). In this work, myocardium was defined by Holzapfel-Ogden constitutive law. Therefore, the objectives of the study were (a) to estimate the ranges of the constitutive parameters for healthy human myocardium using non-invasive routine clinical data, and (b) to investigate the effect of geometry, LV end-diastolic pressure (EDP) and fibre orientations on estimated values. In order to avoid invasive measurements and additional scans, LV cavity volume, measured from routine MRI, and empirical pressure-normalised-volume relation (Klotz-curve) were used as clinical data. Finite element modelling, response surface method and genetic algorithm were used to inversely estimate the constitutive parameters. Due to the ill-posed nature of the inverse optimisation problem, the myocardial properties was extracted by identifying the ranges of the parameters, instead of finding unique values. Additional sensitivity studies were carried out to identify the effect of LV EDP, fibre orientation and geometry on estimated parameters. Although uniqueness of the solution cannot be achieved, the normal ranges of the parameters produced similar mechanical responses within the physiological ranges. These information could be used in future computational studies for designing heart failure treatments. Graphical abstract.

A Novel Hierarchical Template Matching Model for Cardiac Motion Estimation.

Cardiovascular disease diagnosis and prognosis can be improved by measuring patient-specific in-vivo local myocardial strain using Magnetic Resonance Imaging. Local myocardial strain can be determined by tracking the movement of sample muscles points during cardiac cycle using cardiac motion estimation model. The tracking accuracy of the benchmark Free Form Deformation (FFD) model is greatly affected due to its dependency on tunable parameters and regularisation function. Therefore, Hierarchical Template Matching (HTM) model, which is independent of tunable parameters, regularisation function, and image-specific features, is proposed in this article. HTM has dense and uniform points correspondence that provides HTM with the ability to estimate local muscular deformation with a promising accuracy of less than half a millimetre of cardiac wall muscle. As a result, the muscles tracking accuracy has been significantly (p < 0.001) improved (30%) compared to the benchmark model. Such merits of HTM provide reliably calculated clinical measures which can be incorporated into the decision-making process of cardiac disease diagnosis and prognosis.

Passive diastolic modelling of human ventricles: Effects of base movement and geometrical heterogeneity.

Left-ventricular (LV) remodelling, associated with diastolic heart failure, is driven by an increase in myocardial stress. Therefore, normalisation of LV wall stress is the cornerstone of many therapeutic treatments. However, information regarding such regional stress-strain for human LV is still limited. Thus, the objectives of our study were to determine local diastolic stress-strain field in healthy LVs, and consequently, to identify the regional variations amongst them due to geometric heterogeneity. Effects of LV base movement on diastolic model predictions, which were ignored in the literature, were further explored. Personalised finite-element modelling of five normal human bi-ventricles was carried out using subject-specific myocardium properties. Model prediction was validated individually through comparison with end-diastolic volume and a new shape-volume based measurement of LV cavity, extracted from magnetic resonance imaging. Results indicated that incorporation of LV base movement improved the model predictions (shape-volume relevancy of LV cavity), and therefore, it should be considered in future studies. The LV endocardium always experienced higher fibre stress compared to the epicardium for all five subjects. The LV wall near base experienced higher stress compared to equatorial and apical locations. The lateral LV wall underwent greater stress distribution (fibre and sheet stress) compared to other three regions. In addition, normal ranges of different stress-strain components in different regions of LV wall were reported for five healthy ventricles. This information could be used as targets for future computational studies to optimise diastolic heart failure treatments or design new therapeutic interventions/devices.

Computational modelling of left-ventricular diastolic mechanics: effect of fibre orientation and right-ventricle topology.

Majority of heart failure patients who suffer from diastolic dysfunction retain normal systolic pump action. The dysfunction remodels the myocardial fibre structure of left-ventricle (LV), changing its regular diastolic behaviour. Existing LV diastolic models ignored the effects of right-ventricular (RV) deformation, resulting in inaccurate strain analysis of LV wall during diastole. This paper, for the first time, proposes a numerical approach to investigate the effect of fibre-angle distribution and RV deformation on LV diastolic mechanics. A finite element modelling of LV passive inflation was carried out, using structure-based orthotropic constitutive law. Rule-based fibre architecture was assigned on a bi-ventricular (BV) geometry constructed from non-invasive imaging of human heart. The effect of RV deformation on LV diastolic mechanics was investigated by comparing the results predicted by BV and single LV model constructed from the same image data. Results indicated an important influence of RV deformation which led to additional LV passive inflation and increase of average fibre and sheet stress-strain in LV wall during diastole. Sensitivity of LV passive mechanics to the changes in the fibre distribution was also examined. The study revealed that LV diastolic volume increased when fibres were aligned more towards LV longitudinal axis. Changes in fibre angle distribution significantly altered fibre stress-strain distribution of LV wall. The simulation results strongly suggest that patient-specific fibre structure and RV deformation play very important roles in LV diastolic mechanics and should be accounted for in computational modelling for improved understanding of the LV mechanics under normal and pathological conditions.

Effect of fibre orientation on diastolic mechanics of human ventricle.

Fibre orientation of myocardial wall plays a significant role in ventricular wall stress, which is assumed to be responsible for many cardiac mechanics, including ventricular remodelling, associated with heart failure. Previous studies, conducted to identify the effects of fibre orientation on left -ventricle (LV) diastolic mechanics, used only animal's myocardium properties (no human data) and therefore, may not apply for predicting human cardiac mechanics. In the present study, computational modelling of LV diastole was carried out to investigate the effects of fibre orientation on LV end diastolic pressure volume relation (EDPVR) and wall stress distribution using subject-specific in vivo passive properties of human myocardium for two human hearts. Results indicated that LV inflation increased when fibres were aligned more towards LV longitudinal axis and the effect was more notable when the fibre angle was higher in endocardium than epicardium wall. Changes in fibre angle distribution considerably altered fibre stress distribution of LV wall and the changes were significant in anterior and lateral regions of equatorial and apical locations. Furthermore, the regions of high fibre stress from midwall to endocardium were gradually confined towards endocardium with the decrease in fibre angle. Such information will be useful for future studies/diagnoses of LV mechanics in normal and pathological conditions.

Tricuspid valve repair: durability and risk factors for failure.

OBJECTIVES: To compare durability of tricuspid valve annuloplasty techniques, identify risk factors for repair failure, and characterize survival, reoperation, and functional class of surviving patients. METHODS: From 1990 to 1999, 790 patients (mean age 65 +/- 12 years, 51% New York Heart Association functional class III or IV, and mean right ventricular systolic pressure 56 +/- 18 mm Hg) underwent tricuspid valve annuloplasty for functional regurgitation using 4 techniques: Carpentier-Edwards semi-rigid ring, Cosgrove-Edwards flexible band, De Vega procedure, and customized semicircular Peri-Guard annuloplasty. Of these patients, 89% had concomitant mitral valve surgery. A total of 2245 follow-up transthoracic echocardiograms were retrieved. Tricuspid regurgitation was analyzed, and risk factors for worsening regurgitation were identified, by multivariable ordinal longitudinal methods. RESULTS: Tricuspid regurgitation 1 week after annuloplasty was 3+ or 4+ in 14% of patients. Regurgitation severity was stable across time with the Carpentier-Edwards ring (P =.7), increased slowly with the Cosgrove-Edwards band (P =.05), and rose more rapidly with the De Vega (P =.002) and Peri-Guard (P =.0009) procedures. Risk factors for worsening regurgitation included higher preoperative regurgitation grade, poor left ventricular function, permanent pacemaker, and repair type other than ring annuloplasty. Right ventricular systolic pressure, ring size, preoperative New York Heart Association functional class, and concomitant surgery were not risk factors. Tricuspid reoperation was rare (3% at 8 years), and hospital mortality after reoperation was 37%. CONCLUSIONS: Tricuspid valve annuloplasty did not consistently eliminate functional regurgitation, and across time regurgitation increased importantly after Peri-Guard and De Vega annuloplasties. Therefore, these repair techniques should be abandoned, and transtricuspid pacing leads should be replaced with epicardial leads.

Hemolysis after mitral valve repair: mechanisms and treatment.

BACKGROUND: The objectives of this study were to determine the mechanisms of hemolysis after mitral valve repair and to determine outcomes after surgical treatment (mitral replacement or re-repair). METHODS: Between 1981 and 2002, 32 patients (mean age, 58 years) presented with hemolytic anemia after mitral valve repair for degenerative, rheumatic, or ischemic mitral regurgitation (MR). Three types of annuloplasty were used at the initial mitral valve repair: Cosgrove-Edwards, Carpentier-Edwards, and bovine pericardial (Perigard). The diagnosis and the mechanisms of hemolysis were investigated with laboratory testing and echocardiography. RESULTS: Median interval from initial mitral valve surgery to diagnosis of hemolysis was 3 months (range, 1 week to 4 years). At presentation, mean hematocrit was 27.5% +/- 4.9% and 22 patients (69%) required transfusion. Echocardiographic findings varied. Twenty-four patients (77%) had grade 3 or 4 MR. Mitral regurgitant jet types included fragmentation (11 patients, 34%), acceleration (10, 31%), slow deceleration (5, 16%), collision (4, 13%), and free jet (2, 6%). Mitral valve replacement was performed in 28 patients, mitral valve re-repair in 3, and 1 patient did not undergo reoperation. At reoperation the mitral valve repair was physically intact in 25 of 31 patients (81%). There were 2 hospital deaths in patients having reoperation (6%). Actuarial survival was 95% at 1 year and 85% at 5 years. In 1 patient recurrent mechanical hemolysis developed caused by a perivalvular leak after mitral valve replacement. CONCLUSIONS: Hemolysis is a mode of failure of mitral valve repair. Patients with hemolysis generally present within 3 months of mitral valve repair. Although echocardiographic features varied, most patients had high-grade MR and regurgitant jets that fragmented or accelerated. Mitral valve replacement yields favorable outcomes for patients with hemolysis after mitral valve repair.

Edge-to-edge (Alfieri) mitral repair: results in diverse clinical settings.

BACKGROUND: Complex mitral regurgitation (MR) jets can make repair challenging; edge-to-edge (Alfieri) repair augments the repertoire of repair techniques. Objectives of this study were to demonstrate causes of MR amenable to edge-to-edge repair and to determine safety, obstructive potential, and durability of edge-to-edge repair. METHODS: From January 1997 to October 2001, 224 patients underwent Alfieri repair. Indications included ischemic cardiomyopathy (n = 143, 64%), myxomatous disease (n = 31, 14%), dilated cardiomyopathy (n = 27, 12%), and hypertrophic obstructive cardiomyopathy (n = 14, 6%). Concomitant ring annuloplasty was performed in 188 patients (84%). Two additional patients had takedown of an Alfieri repair in the operating room for obstruction. Preoperative MR was 4+ in 109 patients (50%) and 3+ in 65 (30%). Postoperative and follow-up mitral gradient and return of MR were assessed using 396 transthoracic echocardiograms and longitudinal analyses. RESULTS: Hospital mortality was 2% (5 of 224). Mitral valve mean gradient was low (3.7 mm Hg) and nonprogressive (p = 0.7), although peak gradient rose slightly, from mean 8.4 to 10.0 mm Hg (p = 0.01). During the first 3 postoperative months, absence of MR declined to 40%, and prevalence of 3+ MR increased to 14%, then rose slowly thereafter. Fourteen patients--12 within 2 years--underwent mitral valve reoperation, none for stenosis; 7 patients--6 within 2 years--underwent heart transplantation. CONCLUSIONS: Alfieri mitral repair can be used in a variety of settings with a low risk of creating mitral stenosis. However, in ischemic MR, steadily increasing prevalence of moderately severe and severe regurgitation after edge-to-edge repair suggests other techniques are needed.