Left ventricular restoration devices post myocardial infarction

Even in the era of percutaneous reperfusion therapy, left ventricular (LV) remodeling after myocardial infarction (MI) leading to heart failure remains a major health concern. Contractile dysfunction of the infarcted myocardium results in an increased pressure load, leading to maladaptive reshaping of the LV. Several percutaneous transcatheter procedures have been developed to deliver devices that restore LV shape and function. The purposes of this review are to discuss the spectrum of transcatheter devices that are available or in development for attenuation of adverse LV remodeling and to critically examine the available evidence for improvement of functional status and cardiovascular outcomes.

Unprotected versus protected high-risk percutaneous coronary intervention with the Impella 2.5 in patients with multivessel disease and severely reduced left ventricular function

Selecting a revascularization strategy in patients with multivessel disease (MVD) and severely reduced left ventricular ejection fraction (LVEF) remains a challenge. PCI with Impella 2.5 may facilitate high-risk PCI, however long-term results comparing unprotected versus protected PCI are currently unknown. We sought to evaluate the outcome of patients undergoing protected compared to unprotected percutaneous coronary intervention (PCI) in the setting of MVD and severely reduced LVEF.We included patients with MVD and severely reduced LVEF (≤35%) in this retrospective, single-centre study. Patients that underwent unprotected PCI before the start of a dedicated protected PCI program with Impella 2.5 were compared to patients that were treated with protected PCI after the start of the program. The primary endpoint was defined as major adverse cardiac and cerebrovascular events (MACCE) during a 1-year follow-up. The secondary endpoints consisted of in-hospital MACCE and adverse events.A total of 61 patients (mean age 70.7 ± 10.9 years, 83.6% male) were included in our study, of which 28 (45.9%) underwent protected PCI. The primary endpoint was reached by 26.7% and did not differ between groups (P = .90). In-hospital MACCE (P = 1.00) and in-hospital adverse events (P = .12) also demonstrated no significant differences. Multivariate logistic regression identified procedural success defined as complete revascularization and absence of in-hospital major clinical complications as protective parameter for MACCE (OR 0.17, 95% CI 0.04-0.70, P = .02).Patients with MVD and severely depressed LVEF undergoing protected PCI with Impella 2.5 demonstrate similar in-hospital and one-year outcomes compared to unprotected PCI.

Impact of surgical ventricular restoration on early and long-term outcomes of patients with left ventricular aneurysm: A single-center experience

Left ventricular aneurysm (LVA) is a common complication of myocardial infarction. However, the optimal treatment for LVA remains controversial.In this retrospective study, we analyzed the early and long-term clinical consequences of surgical ventricular restoration on 102 patients who had undergone repair between January, 2005 and January, 2015. The LVA repair approaches comprised of patch plasty (n = 28), linear repair (n = 40), and plication repair (n = 34).Patient demographics were 60.8% male, and the mean age was 60.5 ± 7.2 years. The in-hospital mortality rate was 7.8% (8/102), including 6 patients who died from low cardiac output and 2 from multiorgan failure. During the early postoperative period, left ventricular sizes significantly decreased in the patch plasty and linear repair groups compared with the plication group. In addition, all 3 repair techniques greatly ameliorated left ventricular ejection fraction (P < .05), and there was no significant difference in survival rate between groups (P = .25).Surgical ventricular restoration (linear repair, plication repair, and patch plasty) obtained equivalently appreciable outcomes for cardiac function improvement, perioperative mortality, and survival. Selection of a surgical technique for LVA patients should be optimized to individual patient conditions including the morphological characteristics of the aneurysm and ischemic scar.

[Surgical Cardiac Resynchronization Therapy for Patients with Severe Left Ventricular Systolic Dysfunction]

We applied cardiac resynchronization therapy with an implantable cardioverter-defibrillator( CRT-D) and with concomitant cardiac surgery to 2 patients with left ventricular (LV) systolic dysfunction and dyssynchronous ventricular activation. A patient had severe ischemic dilated cardiomyopathy with coronary artery aneurysms (LV ejection fraction 12%, LV diastolic dimension 81 mm, LV systolic dimension 75 mm and atrial fibrillation, with complete left bundle branch block). Another patient had severe dilated cardiomyopathy with mitral valve regurgitation (LV ejection fraction 25%, LV diastolic dimension 75 mm, LV systolic dimension 61 mm atrial fibrillation, and complete left bundle branch block). Both epicardial LV leads were surgically implanted on the posterolateral wall. CRT-D achieved the resynchronization of the LV contraction, and improved cardiac function. The patients had an uneventful postoperative course and were discharged from hospital after operation. A key advantage of surgical epicardial lead placement is that lead placement is not confined to anatomic branches of the LV venous circulation as is the case with transvenous placement. CRT-D combined with cardiac surgery might be available for patients with LV systolic dysfunction.

Prognostic value of myocardial strain and late gadolinium enhancement on cardiovascular magnetic resonance imaging in patients with idiopathic dilated cardiomyopathy with moderate to severely reduced ejection fraction

BACKGROUND

It has been reported that left ventricular (LV) myocardial strain and late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) imaging have prognostic value in patients with heart failure (HF). However, previous studies included patients with various systolic functions. This study aimed to investigate the prognostic value of LV myocardial strain and LGE on CMR imaging in patients with idiopathic dilated cardiomyopathy (DCM) with reduced ejection fraction (EF < 40%).

METHODS

From a prospectively followed cohort who underwent CMR between November 2008 and December 2015, subjects with LV EF < 40% and a diagnosis of idiopathic DCM were eligible for this study. The CMR images were analyzed for LV and right ventricular (RV) function, presence and extent of LGE, and LV myocardial strain. The primary outcome was a composite of all-cause death and heart transplantation. The secondary outcome was hospitalization for HF.

RESULTS

A total of 172 patients were included, in whom mean LV EF was 23.7 ± 7.9% (EF 30-40% n = 47; EF < 30% n = 125). During a median follow-up of 47 months, the primary outcome occurred in 43 patients (16 heart transplantations, 29 all-cause deaths), and there were 41 hospitalizations for HF. Univariate Cox proportional hazard regression analysis showed that mean arterial pressure, serum sodium concentration, log of plasma NT-proBNP level, and presence of LGE (HR 2.277, 95% CI: 1.221-4.246) were significantly associated with the primary outcome. However, LV strain had no significant association (HR 1.048, 95% CI: 0.945-1.163). Multivariable analysis showed that presence of LGE (HR 4.73, 95% CI: 1.11-20.12) and serum sodium (HR 0.823, 95% CI: 0.762-0.887) were independently associated with the primary outcome.

CONCLUSIONS

LGE in CMR imaging was a good predictor of adverse outcomes for patients with idiopathic DCM and reduced EF. Identification of LGE could thus improve risk stratification in high-risk patients. LV strain had no significant prognostic value in patients with moderate to severe systolic dysfunction.

Levosimendan in Patients with Left Ventricular Dysfunction Undergoing Cardiac Surgery: An Update Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Recent studies suggest that levosimendan does not provide mortality benefit in patients with low cardiac output syndrome undergoing cardiac surgery. These results conflict with previous findings. The aim of the current study is to assess whether levosimendan reduces postoperative mortality in patients with impaired left ventricular function (mean EF ≤ 40%) undergoing cardiac surgery.

METHODS

We conducted a comprehensive search of PubMed, EMBASE, and Cochrane Library Database through November 20, 2017. Inclusion criteria were random allocation to treatment with at least one group receiving levosimendan and another group receiving placebo or other treatments and cardiac surgery patients with a left ventricular ejection fraction of 40% or less. The primary endpoint was postoperative mortality. Secondary outcomes were cardiac index, pulmonary capillary wedge pressure (PCWP), length of intensive care unit (ICU) stay, postoperative atrial fibrillation, and postoperative renal replacement therapy. We performed trial sequential analysis (TSA) to evaluate the reliability of the primary endpoint.

RESULTS

Data from 2,152 patients in 15 randomized clinical trials were analyzed. Pooled results demonstrated a reduction in postoperative mortality in the levosimendan group [RR = 0.53, 95% CI (0.38-0.73), I2 = 0]. However, the result of TSA showed that the conclusion may be a false positive. Secondary outcomes demonstrated that PCWP, postoperative renal replacement therapy, and length of ICU stay were significantly reduced. Cardiac index was greater in the levosimendan group. No difference was found in the rate of postoperative atrial fibrillation.

CONCLUSIONS

Levosimendan reduces the rate of death and other adverse outcomes in patients with low ejection fraction who were undergoing cardiac surgery, but results remain inconclusive. More large-volume randomized clinical trials (RCTs) are warranted.

Feasibility and accuracy of gated blood pool SPECT equilibrium radionuclide ventriculography for the assessment of left and right ventricular volumes and function in patients with left ventricular assist devices

BACKGROUND

Left ventricular assist devices (LVADs) require serial assessment of right and left ventricular (RV & LV) volumes and function. Because the RV is not assisted, its function is a critical determinant of the hemodynamic and contributes significantly to postoperative morbidity and mortality. We evaluated the feasibility and the accuracy of tomographic-equilibrium radionuclide ventriculography (t-ERV) for the assessment of patients with LVADs.

METHODS

Twenty-four patients with LVAD underwent t-ERV. Because of the limited acoustic window, transthoracic echocardiography (TTE) was only feasible in 19 patients. Functional evaluation including six-minute walk test (6MWT) and peak oxygen consumption (POC) was performed in 18 patients. Nine patients underwent a cardiac multidetector computed tomography (MDCT). Eight patients underwent a second evaluation by ERV 4.3 ± 1.4 months later.

RESULTS

Reliability between t-ERV and MDCT for LV end-diastolic volume, LV end-systolic volume, LV ejection fraction, RV end-diastolic volume, RV end-systolic volume, and RV ejection fraction (RVEF) was 0.900 (P = .001), 0.911 (P = .001), 0.765 (P = .021), 0.728 (P = .042), 0.875 (P = .004), and 0.781 (P = .023), respectively. There was no correlation between t-ERV and RV systolic parameters assessed by TTE. RVEF was correlated with POC (R = 0.521; P = .027). A cut-off value of 40% for RVEF measured by t-ERV could discriminate patients with poor functional status (P = .048 for NYHA stage; P = .016 for 6MWT and P = .007 for POC).

CONCLUSION

t-ERV is a simple, reproducible, and an accurate technique for the assessment of RV function in patients with LVADs and warrants consideration in the evaluation and monitoring of symptomatic patients.

Coronary Sinus Rupture Repair: Patency Is Important

We report a case of coronary sinus (CS) injury with a retrograde cardioplegia catheter and repair that compromised CS patency. This resulted in acute global cardiac dysfunction shortly after weaning from bypass, which reversed after patch repair with confirmed CS patency. The case report shows that acute CS occlusion may not be tolerated in some humans.

Effect of continuous exenatide infusion on cardiac function and peri-operative glucose control in patients undergoing cardiac surgery: A single-blind, randomized controlled trial

We performed a randomized controlled trial with the glucagon-like peptide-1 (GLP-1) receptor agonist exenatide as add-on to standard peri-operative insulin therapy in patients undergoing elective cardiac surgery. The aims of the study were to intensify peri-operative glucose control while minimizing the risk of hypoglycaemia and to evaluate the suggested cardioprotective effects of GLP-1-based treatments. A total of 38 patients with decreased left ventricular systolic function (ejection fraction ≤50%) scheduled for elective coronary artery bypass grafting (CABG) were randomized to receive either exenatide or placebo in a continuous 72-hour intravenous (i.v.) infusion on top of standard peri-operative insulin therapy. While no significant difference in postoperative echocardiographic variables was found between the groups, participants receiving exenatide showed improved peri-operative glucose control as compared with the placebo group (average glycaemia 6.4 ± 0.5 vs 7.3 ± 0.8 mmol/L; P < .001; percentage of time in target range of 4.5-6.5 mmol/L 54.8% ± 14.5% vs 38.6% ± 14.4%; P = .001; percentage of time above target range 39.7% ± 13.9% vs 52.8% ± 15.2%; P = .009) without an increased risk of hypoglycaemia (glycaemia <3.3 mmol/L: 0.10 ± 0.32 vs 0.21 ± 0.42 episodes per participant; P = .586). Continuous administration of i.v. exenatide in patients undergoing elective CABG could provide a safe option for intensifying the peri-operative glucose management of such patients.

Intracoronary Administration of Allogeneic Adipose Tissue-Derived Mesenchymal Stem Cells Improves Myocardial Perfusion But Not Left Ventricle Function, in a Translational Model of Acute Myocardial Infarction

BACKGROUND

Autologous adipose tissue-derived mesenchymal stem cells (ATMSCs) therapy is a promising strategy to improve post-myocardial infarction outcomes. In a porcine model of acute myocardial infarction, we studied the long-term effects and the mechanisms involved in allogeneic ATMSCs administration on myocardial performance.

METHODS AND RESULTS

Thirty-eight pigs underwent 50 minutes of coronary occlusion; the study was completed in 33 pigs. After reperfusion, allogeneic ATMSCs or culture medium (vehicle) were intracoronarily administered. Follow-ups were performed at short (2 days after acute myocardial infarction vehicle-treated, n=10; ATMSCs-treated, n=9) or long term (60 days after acute myocardial infarction vehicle-treated, n=7; ATMSCs-treated, n=7). At short term, infarcted myocardium analysis showed reduced apoptosis in the ATMSCs-treated animals (48.6±6% versus 55.9±5.7% in vehicle; P=0.017); enhancement of the reparative process with up-regulated vascular endothelial growth factor, granulocyte macrophage colony-stimulating factor, and stromal-derived factor-1α gene expression; and increased M2 macrophages (67.2±10% versus 54.7±10.2% in vehicle; P=0.016). In long-term groups, increase in myocardial perfusion at the anterior infarct border was observed both on day-7 and day-60 cardiac magnetic resonance studies in ATMSCs-treated animals, compared to vehicle (87.9±28.7 versus 57.4±17.7 mL/min per gram at 7 days; P=0.034 and 99±22.6 versus 43.3±14.7 22.6 mL/min per gram at 60 days; P=0.0001, respectively). At day 60, higher vascular density was detected at the border zone in the ATMSCs-treated animals (118±18 versus 92.4±24.3 vessels/mm2 in vehicle; P=0.045). Cardiac magnetic resonance-measured left ventricular ejection fraction of left ventricular volumes was not different between groups at any time point.

CONCLUSIONS

In this porcine acute myocardial infarction model, allogeneic ATMSCs-based therapy was associated with increased cardioprotective and reparative mechanisms and with better cardiac magnetic resonance-measured perfusion. No effect on left ventricular volumes or ejection fraction was observed.

Posterior wall left ventricular aneurysm repair

Posterior wall aneurysms are a relatively rare form of left ventricular aneurysm that can sometimes involve the mitral valve. This tutorial illustrates the technical aspects of posterior wall left ventricular aneurysm repair.

Methodological approach in adopting off-pump coronary artery bypass surgery in a British cardiothoracic unit: Harefield experience

The theoretical and practical disadvantages of coronary artery bypass graft surgery using cardiopulmonary bypass with cardioplegic arrest are well reported in the literature. Encouraged by our work and others, we adopted a systematic approach to the application of off-pump coronary artery bypass surgery. We aimed to validate the non-selective use of the off-pump technique in all patients and assess the outcome in specific patient groups including: patients with ischaemic left ventricular dysfunction, female and high-risk patients. We investigated specific technical details related to off-pump surgery including: the potential effect of the distortion of the mitral valve on haemodynamic stability intraoperatively and the feasibility of sequential coronary artery bypass grafting using the off-pump technique. We also compared the outcome to the national United Kingdom performance in a risk-stratified manner. An extensive retrospective data review for comparative analysis of outcome was carried out at both local and multi-centre levels. This showed that off-pump surgery was feasible for all patients, and provided a better outcome in patients with ischaemic left ventricular dysfunction, female and high-risk patients. The distortion of the mitral valve contributed to the haemodynamic instability. In conclusion, off-pump surgery is safe and provides better outcome in specific patient groups.

[Left Ventricular Pseudoaneurysm after an Apical Approach Transcatheter Aortic Valve Implantation;Report of a Case]

A 79-years-old woman was diagnosed with severe aortic stenosis and referred to our institution for the purpose of an operation. We decided to perform transfemoral transcatheter aortic valve implantation because of her high frailty due to her age and medication of long-term steroid for chronic rheumatoid arthritis. In the operation, left ventricular perforation occurred by the guide wire and cardiac tamponade was detected. We performed pericardial drainage and controlled bleeding through the 5th intercostal thoracotomy and trasncatheter aortic valve implantation was performed after that. Postoperative computed tomography (CT) demonstrated left ventricular pseudoaneurysm in the apex. We performed re-operation because of the enlargement of pseudoaneurysm. The operation was performed through median sternotomy and the pseudoaneurysm was repaired. The patient was discharged after postoperative CT demonstrated the left ventricular wall repaired.

Anaortic off-pump bilateral internal mammary grafting in severe left ventricular dysfunction - Case report

A 64 years old male diabetic patient with ejection fraction of 16% and renal dysfunction underwent off-pump CABG using both in situ internal mammary artery grafts. Left internal mammary artery was used to bypass left anterior descending artery and right internal mammary artery was used as composite graft. Patient had uneventful recovery and left ventricular ejection fraction improved to 34% within 8 months after surgery. In presence of left ventricular dysfunction, both internal thoracic artery grafting should be preferred for better patency rate and flow reserve. This is the first ever case report of anaortic off-pump bilateral internal thoracic artery grafting in a patient with left ventricular ejection fraction less than 20%.

Recovery of Left Ventricular Function After Percutaneous Coronary Intervention Compared to Coronary Artery Bypass Grafting in Patients with Multi-Vessel Coronary Disease and Left Ventricular Dysfunction

Recovery of left ventricular (LV) function after revascularization has been described for coronary artery bypass grafting (CABG); however, LV recovery after percutaneous coronary intervention (PCI), and how it compares to CABG has not been well described in the literature. The aim of this single center retrospective study was to evaluate LV recovery in patients with severely reduced LV function undergoing PCI compared to those undergoing CABG. Patients with LV ejection fraction (LVEF) < 40% and multivessel coronary artery disease (CAD) undergoing revascularization with either CABG (n=16) or PCI (n=176), and with 12 months of follow up data were included in the study. LVEF at baseline exhibited significant differences between PCI (28.5 ± 8.0) and CABG (24.2 ± 6.8) groups (P=.05). LVEF recovery at 6-month follow up showed no difference between PCI and CABG groups. LVEF recovery differences at one-year follow-up was significantly different between PCI (4.82) and CABG (15.25) groups (P=.005). Patients with severely reduced LV function undergoing multivessel PCI had a statistically significant increase in LVEF over time; however patients undergoing CABG demonstrated greater gains in LVEF over the same time period. Surgical revascularization with CABG may be a procedure of choice in patients with depressed LV function and multivessel CAD.

Association between High Endocardial Unipolar Voltage and Improved Left Ventricular Function in Patients with Ischemic Cardiomyopathy

We know that endocardial mapping reports left ventricular electrical activity (voltage) and that these data can predict outcomes in patients undergoing traditional revascularization. Because the mapping data from experimental models have also been linked with myocardial viability, we hypothesized an association between increased unipolar voltage in patients undergoing intramyocardial injections and their subsequent improvement in left ventricular performance. For this exploratory analysis, we evaluated 86 patients with left ventricular dysfunction, heart-failure symptoms, possible angina, and no revascularization options, who were undergoing endocardial mapping. Fifty-seven patients received bone marrow mononuclear cell (BMC) injections and 29 patients received cell-free injections of a placebo. The average mapping site voltage was 9.7 ± 2 mV, and sites with voltage of ≥6.9 mV were engaged by needle and injected (with BMC or placebo). For all patients, at 6 months, left ventricular ejection fraction (LVEF) improved, and after covariate adjustment this improvement was best predicted by injection-site voltage. For every 2-mV increase in baseline voltage, we detected a 1.3 increase in absolute LVEF units for all patients (P=0.038). Multiple linear regression analyses confirmed that voltage and the CD34(+) count present in bone marrow (but not treatment assignment) were associated with improved LVEF (P=0.03 and P=0.014, respectively). In an exploratory analysis, higher endocardial voltage and bone marrow CD34(+) levels were associated with improved left ventricular function among ischemic cardiomyopathy patients. Intramyocardial needle injections, possibly through stimulation of angiogenesis, might serve as a future therapy in patients with reduced left ventricular function and warrants investigation.

Persistent reduced myocardial deformation in neonates after CoA repair

INTRODUCTION

Surgical repair of coarctation of the aorta (CoA) is a safe procedure in children, however the condition is known for its potential recurrence and other related complications. The available evidence shows abnormal intrinsic properties of the aorta in CoA, thus suggesting additional effect, even after CoA repair, on left ventricular (LV) function. Accordingly, we sought to obtain a better understanding of LV myocardial mechanics in very early-corrected CoA using two-dimensional STE.

METHODS AND RESULTS

We retrospectively studied 21 patients with corrected CoA at a median age of 9 (2-53) days at three time points: 1) just before intervention, 2) at short-term follow-up and 3) at medium-term follow-up after intervention and compared them with normal values. Speckle tracking analysis was conducted via vendor independent software, Tomtec. After intervention, LV function significantly improved (from -12.8±3.9 to -16.7±1.7; p<0.001), however normal values were not reached even at medium term follow-up (-18.3±1.7 vs. -20±1.6; p=0.002). Medium term longitudinal strain correlated with pre intervention EF (r=0.58, p=0.006). Moreover, medium term subnormal values were more frequently associated with bicuspid aortic valve (33.3% vs. 66.6%; p<0.05).

CONCLUSION

LV myocardial function in neonates with CoA can be feasibly evaluated and followed up by speckle tracking echocardiography. LV subendocardial dysfunction however, remains in early infancy coarctation long after repair. Long-term follow-up through adulthood using myocardial deformation measurements should shed light on the natural history and consequences of this anomaly.

Off-Pump Revascularization for Significant Left Ventricular Dysfunction

Left ventricular dysfunction is a predictor of perioperative morbidity and mortality in on-pump coronary artery bypass grafting. Obligatory global myocardial ischemia and injury induced during crossclamping as well as adverse systemic effects of cardiopulmonary bypass may induce a disproportionately greater overall physiologic insult in patients with poor ventricular function. All patients undergoing nonemergency off-pump coronary artery bypass by a single surgeon during an 18-month period were retrospectively analyzed. Two groups with preoperative ejection fraction classified as poor (10%–35%; n = 31) or normal (55%–80%; n = 60) were compared. The mean ejection fractions were 26% ± 1% and 63% ± 1% respectively, p < 0.000001. In those with significant left ventricular dysfunction, there were 2.8 ± 0.1 grafts per patient, time to extubation was 8.4 ± 1.2 hours, and discharge was after 4.9 ± 0.6 days. These results were statistically equivalent to those in the group with normal left ventricular function. There was no intraaortic balloon pump insertion or mortality in either group. This technique provides an effective means of safely revascularizing patients with significant left ventricular dysfunction, and it may provide a valuable alternative approach in patients with ischemic cardiomyopathy.

Effect of Chordal Preservation on Left Ventricular Function

Chordopapillary apparatus preservation was compared with valve-excising mitral valve replacement in a retrospective analysis of 360 patients, of whom 98 had total or partial chordal preservation and 262 had the conventional operation. No significant differences were seen in age, sex, pathology, crossclamp or cardiopulmonary bypass times between the 3 groups. Left ventricular fractional shortening decreased significantly in patients whose valves had been excised completely, whereas it remained unchanged in patients with either partial or total chordal conservation. There was a survival benefit for patients undergoing leaflet preservation (92% vs. 80% for conventional excision at 5 years; p = 0.001). Chordal preservation during valve replacement for mitral valve disease improves survival, enhances functional status, preserves left ventricular geometry and function, and improves overall cardiac performance. Preservation of the posterior leaflet alone offers excellent results that are comparable to those of patients with total chordal preservation.

Minimally Invasive Aortic Valve Replacement in Left Ventricular Dysfunction

The safety and benefit of minimally invasive aortic valve replacement in patients with left ventricular dysfunction has not been well investigated. We conducted a retrospective review of 140 patients with ejection fraction ≤ 40% who underwent isolated aortic valve replacement between July 1996 and March 2005. Aortic valve replacement was performed via an upper hemisternotomy in 73 patients and via a full sternotomy in 67. Two matched cohorts of 41 patients each were constructed using propensity score analysis, and the outcomes were compared. There was no significant difference in operative mortality (hemisternotomy, 2.4% vs 4.8% for full sternotomy), incidence of postoperative complications, blood transfusion requirement, length of hospital stay, or discharge to home rates. Aortic valve replacement via an upper hemisternotomy can be performed safely, even in patients with left ventricular dysfunction, with morbidity and mortality outcomes similar to those of a full sternotomy.

Early Result of Heart Transplantation in Japan: Osaka University Experience

Since the new organ transplantation law was established in 1997, 17 heart transplantations have been performed in Japan, 7 of which were carried out at Osaka University Hospital. Recipient diagnosis was dilated cardiomyopathy in 2, dilated phase of hypertrophic cardiomyopathy in 4, and post-myocarditis cardiomyopathy in 1. Ages ranged from 8 to 49 years with a mean of 35.3 years. Five patients were bridged with a left ventricular assist device. The waiting period was 182–977 days (mean, 643 days). There was no early or late death during follow-up of 1–4.8 years. Under a standard triple-drug regimen using mycophenolate, there were 3 rejection episodes greater than grade 3 in 2 patients, and humoral rejection requiring plasmapheresis in one. A young boy whose donor was a hemodynamically compromised adult developed neurological sequelae after resuscitation following ventricular tachycardia. All patients were discharged and went back to work or their regular daily life. Although the donor shortage is still severe in Japan, the resumption of heart transplantation has been satisfactory, and left ventricular assist devices have played a crucial role.

Left ventricular long axis strain: a new prognosticator in non-ischemic dilated cardiomyopathy?

BACKGROUND

Long axis strain (LAS) has been shown to be a fast assessable parameter representing global left ventricular (LV) longitudinal function in cardiovascular magnetic resonance (CMR). However, the prognostic value of LAS in cardiomyopathies with reduced left ventricular ejection fraction (LVEF) has not been evaluated yet.

METHODS AND RESULTS

In 146 subjects with non-ischemic dilated cardiomyopathy (NIDCM, LVEF ≤45 %) LAS was assessed retrospectively from standard non-contrast SSFP cine sequences by measuring the distance between the epicardial border of the left ventricular apex and the midpoint of a line connecting the origins of the mitral valve leaflets in end-systole and end-diastole. The final values were calculated according to the strain formula. The primary endpoint of the study was defined as a combination of cardiac death, heart transplantation or aborted sudden cardiac death and occurred in 24 subjects during follow-up. Patients with LAS values > -5 % showed a significant higher rate of cardiac events independent of the presence of late gadolinium enhancement (LGE). The multivariate Cox regression analysis revealed that LVEDV/BSA (HR: 1.01, p < 0.05), presence of LGE (HR: 2.51, p < 0.05) and LAS (HR: 1.28, p < 0.05) were independent predictors for cardiac events. In a sequential cox regression analysis LAS offered significant incremental information (p < 0.05) for the prediction of outcome in addition to LGE and LVEDV/BSA. Using a dichotomous three point scoring model for risk stratification, including LVEF <35 %, LAS > -10 % and the presence of LGE, patients with 3 points had a significantly higher risk for cardiac events than those with 2 or less points.

CONCLUSION

Assessment of long axis function with LAS offers significant incremental information for the prediction of cardiac events in NIDCM and improves risk stratification beyond established CMR parameters.

Coronary-Artery Bypass Surgery in Patients with Ischemic Cardiomyopathy

BACKGROUND

The survival benefit of a strategy of coronary-artery bypass grafting (CABG) added to guideline-directed medical therapy, as compared with medical therapy alone, in patients with coronary artery disease, heart failure, and severe left ventricular systolic dysfunction remains unclear.

METHODS

From July 2002 to May 2007, a total of 1212 patients with an ejection fraction of 35% or less and coronary artery disease amenable to CABG were randomly assigned to undergo CABG plus medical therapy (CABG group, 610 patients) or medical therapy alone (medical-therapy group, 602 patients). The primary outcome was death from any cause. Major secondary outcomes included death from cardiovascular causes and death from any cause or hospitalization for cardiovascular causes. The median duration of follow-up, including the current extended-follow-up study, was 9.8 years.

RESULTS

A primary outcome event occurred in 359 patients (58.9%) in the CABG group and in 398 patients (66.1%) in the medical-therapy group (hazard ratio with CABG vs. medical therapy, 0.84; 95% confidence interval [CI], 0.73 to 0.97; P=0.02 by log-rank test). A total of 247 patients (40.5%) in the CABG group and 297 patients (49.3%) in the medical-therapy group died from cardiovascular causes (hazard ratio, 0.79; 95% CI, 0.66 to 0.93; P=0.006 by log-rank test). Death from any cause or hospitalization for cardiovascular causes occurred in 467 patients (76.6%) in the CABG group and in 524 patients (87.0%) in the medical-therapy group (hazard ratio, 0.72; 95% CI, 0.64 to 0.82; P<0.001 by log-rank test).

CONCLUSIONS

In a cohort of patients with ischemic cardiomyopathy, the rates of death from any cause, death from cardiovascular causes, and death from any cause or hospitalization for cardiovascular causes were significantly lower over 10 years among patients who underwent CABG in addition to receiving medical therapy than among those who received medical therapy alone. (Funded by the National Institutes of Health; STICH [and STICHES] ClinicalTrials.gov number, NCT00023595.).

Left Ventricular Deformation and Myocardial Fibrosis in Patients With Advanced Heart Failure Requiring Transplantation

PURPOSE

To evaluate potential relationships between different components of left ventricular (LV) function and histopathological evidence for myocardial fibrosis in patients undergoing heart transplantation.

METHODS

The study population included patients with advanced heart failure, referred for an echocardiographic examination before heart transplantation. Traditional LV function measurements and global longitudinal strain (GLS) by speckle tracking echocardiography, averaging all LV segments in 4-, 2-, and 3-chamber views were obtained in all subjects. LV tissue samples were obtained from all patients who underwent heart transplantation. Myocardial fibrosis was assessed using Masson's staining.

RESULTS

Of 106 patients referred for cardiac transplantation, 47 underwent cardiac transplantation and were enrolled in the study. LV myocardial fibrosis and its grade strongly correlated with GLS (r = 0.75, P = .0001), modestly with global circumferential strain and LV torsion (r = 0.61, P = .001 and r = 0.52, P = .01, respectively) and weakly with mitral S' wave (r = -0.41; P = .01) and mitral annular plane systolic excursion (r = -0.35; P = .05) but did not correlate with LV ejection fraction (r = -0.12; P = NS). GLS had the strongest accuracy for detecting LV fibrosis (area under the curve, 0.92). None of the echo parameters correlated with patient's exercise capacity.

CONCLUSION

Global longitudinal strain is the most accurate LV global function measure that correlates with the extent of myocardial fibrosis in patients with advanced systolic HF requiring heart transplantation.

Left Ventricular Outflow Tract Arrhythmias: Clinical Characteristics and Site of Origin

BACKGROUND

Left ventricular outflow tract (LVOT) arrhythmias are increasingly recognized. Data regarding the distribution of the sites of origin (SOO) of the arrhythmias are sparse.

OBJECTIVES

To describe the clinical characteristics of patients with LVOT arrhythmias and the distribution of their SOO.

METHODS

All 42 consecutive patients with LVOT arrhythmias who underwent radiofrequency (RF) ablation during the period 2000-2014 were included. SOO identification was based on mapping activation, pace mapping and a 3D mapping system in eight patients.

RESULTS

The study group comprised 28 males (66.7%) and 14 females, the mean age was 55 ± 15.4 years. Most patients (76%) were symptomatic. All suffered from high grade ventricular arrhythmias. Left ventricular (LV) dysfunction (ejection fraction ≤ 50%) was observed in 15 patients (35.7%), of whom 14 (93.3%) were males. The left coronary cusp (LCC) was the most common arrhythmia SOO (64.3%). Other locations were the right coronary cusp (RCC), the junction of the RCC-LCC commissure, aortic-mitral continuity, endocardial-LVOT, and a coronary sinus branch. Acute successful ablation was achieved in 29 patients (69%) and transient arrhythmia abolition in 40 (95.2%). There was a trend for a higher success rate using cooled tip ablation catheters as compared to standard catheters. The ablation procedure significantly improved LV function in all patients with tachycardiomyopathy.

CONCLUSIONS

LVOT arrhythmias mostly originate from the LCC and are associated with LV dysfunction in 36% of patients. Knowledge regarding the prevalence of the anatomic origin of the LVOT arrhythmias may help achieve successful ablation. The use of cooled tip ablation catheters might have beneficial effects on the success rate of the procedure.