A novel method of prosthetic leaflet modification to enable transcatheter mitral valve-in-valve replacement

Left ventricular outflow tract (LVOT) obstruction from the displaced prosthetic anterior mitral leaflet is a life-threatening complication that can occur during valve-in-valve (ViV) transcatheter mitral valve replacement (TMVR). Laceration of the anterior mitral leaflet to prevent outflow obstruction is a well-established transcatheter technique to mitigate the risk of LVOT obstruction in high-risk anatomies. In this report, we present a novel transseptal technique of prosthetic leaflet modification to prevent LVOT obstruction during ViV TMVR.

First Application of the LAMPOON Procedure to a Surgical Mitral Bioprosthesis

A cardiogenic shock patient with a history of a surgical mitral valve replacement presented to the hospital with critical mitral stenosis with thickening of prosthetic valve leaflets and thrombus in left atrial appendage. We considered TMVR inside of the degenerated bioprosthetic valve. However, there were two concerns during TMVR based on multimodality imaging assessment: 1) LVOT obstruction due to the surgical bioprosthetic leaflet, 2) stroke due to left atrial appendage thrombus. We performed TMVR with LAMPOON (laceration of the anterior leaflet of the surgical valve to prevent left ventricular outflow tract obstruction) for the bioprosthesis using cerebral protection. While the LAMPOON procedure has developed to prevent LVOT obstruction by the native anterior mitral leaflet during transcatheter mitral valve-in-ring or valve-in-mitral annular calcification, this is the first case that illustrates its use for mitral valve-in-valve replacement.

Hypertrophic Obstructive Cardiomyopathy: Comparison of Outcomes After Myectomy or Alcohol Ablation

Introduction and Objectives

The risk of ventricular arrhythmia and heart failure in patients with hypertrophic obstructive cardiomyopathy (HOCM) is much higher than that in the general population. More and more pieces of evidence showed that HOCM is the leading cause of sudden cardiac death in young people. We reported our experience in a study, comparing surgical myectomy, alcohol septal ablation (ASA), and medical therapy.

Methods

The original cohort included 965 consecutive patients with HOCM. The patients were divided into three groups according to treatment strategies: myectomy group (n = 502), ASA group (n = 138), and medical treatment group (n = 325). The median follow-up duration was 42.99 ± 18.32 months, and the primary endpoints were all-cause mortality and heart transplantation.

Results

Both in short- and long-term observations, surgical myectomy reduced the left ventricular outflow tract (LVOT) gradients more effectively (7 days, 16.15 ± 12.07 mmHg vs. 42.33 ± 27.76 mmHg, p < 0.05; 1 year, 14.65 ± 13.18 mmHg vs. 41.17 ± 30.76 mmHg, p < 0.05). Among the three groups, the patients in the medical treatment group were at a higher risk of mortality and cardiac transplantation (vs. the myectomy group, p < 0.001 by log-rank test; vs. the alcohol septal ablation group, p = 0.017 by log-rank test), and the myectomy group shows a lower risk of reaching the primary endpoint than the two other groups. In the multivariate Cox regression analysis, previous atrial fibrillation (AF), N terminal pro B type natriuretic peptide (NT-pro-BNP), and surgical myectomy predicted an HOCM prognosis. However, the impact of surgical myectomy on HOCM prognosis seems to be limited to the <56 years group.

Conclusions

The patients with medical treatments seemed to suffer from the highest risk of achieving an all-cause mortality and the endpoint of heart transplantation. In the long-term survival and clinical outcome, myectomy seemed better than alcohol septal ablation, especially the younger patients. Due to the less-controllable degree, periprocedural complication frequency after alcohol septal ablation was higher, compared with myectomy. Furthermore, gradients after myectomy are lower at late follow-up. To sum up, when selecting treatment strategies, the patients should be individually evaluated by a multidisciplinary team of cardiologists and surgeons.

Peri-procedural Trans-esophageal Echocardiographic Sizing of the Native Left Ventricular Outflow Tract During Edwards INTUITY Valve Implantation

Background: The Edwards INTUITY rapid deployment valve was anchored on the left ventricular outflow tract (LVOT) by radial force akin to transcatheter balloon-expandable valves. This design feature facilitates minimally invasive and complex procedures but comes at the price of compressing the atrioventricular conduction bundle and potential requirement for pacemaker implantation.

Methods: A retrospective observational study was conducted on 30 consecutive patients who received the INTUITY valve at our institution from August 2018 to January 2021. Demographical, clinical, and echocardiographic parameters were collected for 90 days post-operatively. The diameter of the native LVOT at the landing site of the sub-annular stent was retrospectively measured using archived trans-esophageal echocardiographic images. A line was drawn from the inner edge of the septal endocardium to the inner edge of the anterior mitral leaflet in mid-systole, parallel to the aortic annulus, 6–8 mm apical to the aortic annulus depending on the valve size and the corresponding stent length. Risk factors associated with new onset conduction disturbances, defined as the occurrence of bundle branch block or complete heart block, were analyzed.

Results: Operative mortality was 3.3%. Pre-operatively, permanent pacemakers were required for two patients who were excluded from the subsequent analysis. New onset conduction disturbances occurred in four of the remaining 28 patients (14.3%). This included two incidences of persistent left bundle branch block and two incidences of permanent pacemaker implantation due to complete heart block. Univariate analysis identified over-sizing of the native LVOT by 5 mm or more as a significant risk factor associated with conduction disturbance.

Conclusion: During INTUITY vale implantation, in addition to the aortic annulus, the landing site of the sub-annular stent within the native LVOT should also be sized pre-bypass. Over-sizing the native LVOT by 5 mm or more was associated with an increased risk of new onset conduction disturbances and should be avoided.

Neo-LVOT and Transcatheter Mitral Valve Replacement: Expert Recommendations

With the advent of transcatheter mitral valve replacement (TMVR), the concept of the neo-left ventricular outflow tract (LVOT) was introduced and remains an essential component of treatment planning. This paper describes the LVOT anatomy and provides a step-by-step computed tomography methodology to segment and measure the neo-LVOT while discussing the current evidence and outstanding challenges. It also discusses the technical and hemodynamic factors that play a major role in assessing the neo-LVOT. A summary of expert-based recommendations about the overall risk of LVOT obstruction in different scenarios is presented along with the currently available methods to reduce the risk of LVOT obstruction and other post-procedural complications.

Treatment of severe aortic stenosis and left ventricular outflow tract mass with transcutaneous aortic valve implantation: a case report

Background

Percutaneous implantation of aortic valve for severe aortic stenosis (AS) in the presence of pedunculated mobile left ventricular outflow tract (LVOT) mass not reported before. In this case report, we address the feasibility of this procedure.

Case summary

An 80-year-old patient who presented with presyncope, transthoracic echocardiogram (TTE), and transoesophageal echocardiography (TOE) revealed severe calcific AS and LVOT mass measuring 2.1*1.5 cm. The patient was turned down for surgery. It was decided that transcatheter aortic valve implantation (TAVI) be performed because the valve compresses the mass against the proximal part of the interventricular septum. The mass peduncle was 1.4 cm, and it was 4 mm away from the annulus. This meant the valve was needed to be deployed 18 mm below the annulus to cover the mass completely. Gentle manipulation and direct valve deployment without preballoon dilation to decrease the possibility of fragment embolization were necessary. Self-expandable core valve deployed as low as possible, after initial deployment, the distance of LVOT covered by the valve measured by TOE 1.66 cm, the whole mass was covered, then the valve was fully deployed. The patient was extubated in the catheterization room; there was no clinical evidence of embolization. The patient was discharged home after 2 days. A follow-up TTE after 6 months showed a well-functioning valve and the LVOT mass then disappeared.

Discussion

Pedunculated LVOT mass should be resected surgically. In high-risk surgical patients, direct TAVI to compress the mass is feasible in experienced canters. The safety issues need more research and more cases to judge. Transoesophageal echocardiography during the procedure is mandatory to guide the valve position.

Balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction (BATMAN): A novel technique for patients undergoing transcatheter mitral valve replacement

INTRODUCTION

Transcatheter mitral valve replacement (TMVR) is an option for patients at high risk for mitral valve replacement or repair via sternotomy or left thoracotomy approach. TMVR carries up to 22% risk of left ventricular outflow tract (LVOT) obstruction. Severe LVOT obstruction can have devastating hemodynamic and clinical consequences.

HYPOTHESIS

We previously presented a novel technique to prevent LVOT obstruction during transapical retrograde mitral valve replacement, by penetrating and ballooning the anterior mitral leaflet (AML), resulting in creation of a "hole" and posterior translocation of AML, then deploying the valve.

METHODS

Three patients underwent TMVR at Saint Louis University for severe mitral regurgitation after being deemed too high risk for surgery, and not candidates for a Mitra-clip procedure. These patients were deemed to be at risk for LVOT obstruction based on the preprocedural evaluation. Via transapical approach, a needle was advanced "through," perforating the AML and wire was placed in the left atrium. Over the wire, an 20-mm valvuloplasty balloon was positioned "within" the anterior leaflet and inflated leading to translocation of the AMVL. Then the valve was deployed.

RESULTS

This novel technique has been performed on three patients at our institution. Sapien S3 transcatheter valves were used in all three patients, with 100% procedural success rate. Intraoperative TEE demonstrated no significant LVOT obstruction, cardiopulmonary bypass time was 42-44 min.

CONCLUSION

The balloon assisted translocation of the mitral anterior leaflet to prevent left ventricular outflow obstruction technique described here may offer the option of transcatheter mitral valve implantation in patients at high risk of LVOT obstruction. A variation of this technique to allow application in cases with transseptal approach is under investigation.

Evaluation of Hypertrophic Cardiomyopathy: Newer Echo and MRI Approaches

PURPOSE OF REVIEW

This review discusses the basic and evolving echocardiographic and cardiac magnetic resonance (CMR) approaches in the diagnosis and management of patients with hypertrophic cardiomyopathy (HCM).

RECENT FINDINGS

Newer imaging technologies and techniques in both echocardiography and CMR have proved to add incremental value to our understanding of HCM. 3D reconstruction in echocardiography and CMR allows for more accurate morphological and volumetric assessment of the left ventricle. Echocardiographic and CMR-based left atrial assessment, including for its mechanical properties, has been shown to be correlated to outcomes and development of atrial fibrillation. Tissue characterization and scar burden quantification by late gadolinium enhancement on CMR has revolutionized our understanding of fibrotic processes in HCM and their contribution to disease severity and clinical outcomes. Cardiac imaging plays a crucial role in HCM patients. Using echocardiography and CMR as complementary modalities allows for improved diagnostics, optimization of treatment, and better prognostication.

Mitral valve velocity time integral and passive leg raise as a measure of volume responsiveness

Background

Fluid responsiveness is an important topic for clinicians. Aggressive hydration has been shown to lead to worse outcomes. The aim of this study was to investigate the sensitivity and specificity of mitral valve (MV) velocity time integral (VTI) as a non-invasive marker of volume responsiveness.

Methods

This was a prospective observational study conducted in a tertiary emergency department. End-stage renal disease patients presenting to the emergency department requiring emergent hemodialysis were enrolled. A focused echocardiogram was done on enrolled patients. Two sets of measurements were obtained before and after hemodialysis. During each scanning session, the left ventricular outflow tract and the mitral valve VTI were obtained before and after a passive leg raise maneuver.

Results

54 patients were enrolled, of which, 30 (55%) were male. The mean age was 47.4 years. The mean volume of fluid removed was 3.89 ± 0.91 L. All patients had a diagnosis of hypertension, 22 (41%) patients were diabetic, 14 (26%) patients had coronary artery disease, and 19 (35%) patients had congestive heart failure. The mean change in LVOT VTI was 1.83% (95% CI 0.12–3.55) in the pre-dialysis group and 15.05% (95% CI 12.76–17.34) in the post-hemodialysis cohort. The mean change in MV VTI was 3.74% (95% CI 2.84–4.65) in the pre-dialysis cohort and 12.95% (95% CI 11.50–14.39) in the post-dialysis cohort. For patients who had < 4 L removed, the mean delta LVOT VTI post-hemodialysis was 12.64% (95% CI 9.79–15.49) and the mean delta MV VTI was 10.48% (95% CI 8.28–12.69). For patients who had > 4 L removed, the mean delta LVOT VTI was 16.84% (95% CI 13.47–20.22) and the mean MV VTI was 14.77% (95% CI 13.03–16.51). Mitral valve VTI with PLR was found to have a sensitivity of 89.18% and a specificity of 94.11% in detecting volume responsiveness.

Conclusion

Mitral valve velocity time integral in conjunction with passive leg raise seem to correlate with volume responsiveness in hemodialysis patients.

Left ventricular outflow tract pseudoaneurysm diagnosed with point-of-care ultrasound in the emergency department

Left ventricular outflow tract pseudoaneurysms are a rare but life-threatening disorder, often caused by complications of cardiac surgery or myocardial infarction. We present a case report of a patient with no prior risk factors who presented with a six-month history of progressive exertional dyspnea, bilateral leg swelling and cough. Point-of-care ultrasound revealed an unexpected outpouching of the left ventricle. He was diagnosed with a left ventricular outflow tract pseudoaneurysm and subsequently went into cardiogenic shock secondary to extension of pseudoaneurysm causing extrinsic compression of the coronary arteries. The patient underwent successful emergency surgical repair and made a full recovery.

Awareness of 'Systolic Anterior Motion' in Different Conditions

Perioperative echocardiography, especially transesophageal echocardiography, is of paramount importance in evaluating and managing refractory hypotension, a potential cause of which is systolic anterior motion (SAM) of anterior mitral leaflet. Dynamically moving anterior mitral valve leaflet towards the left ventricular outflow tract (LVOT) is described as SAM. Although SAM was initially observed in patients with hypertrophic cardiomyopathy, it can also be seen in patients with complex dynamic anatomy of the left ventricle. Interestingly, SAM may or may not give rise to clinically significant LVOT obstruction. Hence, it is of paramount importance for perioperative physician to know such ‘dynamic SAM’ which can potentially and significantly affect and alter perioperative management.

Hypertrophic Cardiomyopathy-Past, Present and Future

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy with a prevalence of 1 in 500 in the general population. Since the first pathological case series at post mortem in 1957, we have come a long way in its understanding, diagnosis and management. Here, we will describe the history of our understanding of HCM including the initial disease findings, diagnostic methods and treatment options. We will review the current guidelines for the diagnosis and management of HCM, current gaps in the evidence base and discuss the new and promising developments in this field.

Transcatheter aortic valve implantation in the elderly: who to refer?

In recent years, experience with transcatheter aortic valve implantation has led to improved outcomes in elderly patients with severe aortic stenosis (AS) who may not have previously been considered for intervention. These patients are often frail with significant comorbid conditions. As the prevalence of AS increases, there is a need for improved assessment parameters to determine the patients most likely to benefit from this novel procedure. This review discusses the diagnostic criteria for severe AS and the trials available to aid in the decision to refer for aortic valve procedures in the elderly.

Relative efficacy of catheter ablation vs antiarrhythmic drugs in treating premature ventricular contractions: a single-center retrospective study

BACKGROUND

It is unknown whether radiofrequency ablation (RFA) or antiarrhythmic therapy is superior when treating patients with symptomatic premature ventricular contractions (PVCs).

OBJECTIVE

To determine the relative efficacy of RFA and antiarrhythmic drugs (AADs) on PVC burden reduction and increasing left ventricular systolic function.

METHODS

Patients with frequent PVCs (>1000/24 h) were treated either by RFA or with AADs from January 2005 through December 2010. Data from 24-hour Holter monitoring and echocardiography before and 6-12 months after treatment were compared between the 2 groups.

RESULTS

Of 510 patients identified, 215 (40%) underwent RFA and 295 (60%) received AADs. The reduction in PVC frequency was greater by RFA than with AADs (-21,799/24 h vs -8,376/24 h; P < .001). The left ventricular ejection fraction (LVEF) was increased significantly after RFA (53%-56%; P < .001) but not after AAD (52%- 52%; P = .6) therapy. Of 121 (24%) patients with reduced LVEF, 39 (32%) had LVEF normalization to 50% or greater. LVEF was restored in 25 of 53 (47%) patients in the RFA group compared with 14 of 68 (21%) patients in the AAD group (P = .003). PVC coupling interval less than 450 ms, less impaired left ventricular function, and RFA were independent predictors of LVEF normalization performed by using multivariate analysis.

CONCLUSION

RFA appears to be more effective than AADs in PVC reduction and LVEF normalization.

Elevated left ventricular outflow tract velocities on exercise stress echocardiography may be a normal physiologic response in healthy youth

BACKGROUND

Children with heart disease are at risk for sudden death during exercise, yet decisions regarding sports participation are often based on resting data. Acceleration across the left ventricular outflow tract (LVOT) assessed on stress echocardiography may suggest a diagnosis of hypertrophic cardiomyopathy in patients in whom it is not otherwise obvious. However, the range of peak velocities across the LVOT in healthy youth is unknown. The aim of this study was to describe LVOT velocities with maximal exercise in this age group.

METHODS

Subjects up to 18 years old were prospectively enrolled if they had normal results on resting echocardiography and were undergoing exercise testing for other reasons. Subjects with significant comorbidities, suspected cardiomyopathy, or family histories of cardiomyopathy were excluded. Peak LVOT velocities were measured in the upright position using continuous-wave Doppler immediately after maximal exercise.

RESULTS

Fifty subjects (mean age, 13.8 ± 2.8 years) were included. Twenty-eight (56%) were male, and 40 (80%) were Caucasian. The median peak LVOT velocity measured immediately after exercise was 2.5 m/sec (range, 1.3-5.9 m/sec). Sixteen subjects (32%) developed peak LVOT velocities of ≥3 m/sec. Twelve of the 16 (75%) with elevated velocities had a dynamic outflow tract Doppler pattern, of whom eight had evidence of intracavitary narrowing on two-dimensional echocardiography.

CONCLUSIONS

The development of significant exercise-induced LVOT velocities may be a normal physiologic finding in healthy youth. The measurement of LVOT velocities alone with maximal exercise may not help distinguish patients with hypertrophic cardiomyopathy from healthy children.

The complex nature of discordant severe calcified aortic valve disease grading: new insights from combined Doppler echocardiographic and computed tomographic study

OBJECTIVES

With concomitant Doppler echocardiography and multidetector computed tomography (MDCT) measuring aortic valve calcification (AVC) load, this study aimed at defining: 1) independent physiologic/structural determinants of aortic valve area (AVA)/mean gradient (MG) relationship; 2) AVC thresholds best associated with severe aortic stenosis (AS); and 3) whether, in AS with discordant MG, severe calcified aortic valve disease is generally detected.

BACKGROUND

Aortic stenosis with discordant markers of severity, AVA in severe range but low MG, is a conundrum, unresolved by outcome studies.

METHODS

Patients (n = 646) with normal left ventricular ejection fraction AS underwent Doppler echocardiography and AVC measurement by MDCT. On the basis of AVA-indexed-to-body surface area (AVAi) and MG, patients were categorized as concordant severity grading (CG) with moderate AS (AVAi >0.6 cm²/m², MG <40 mm Hg), severe AS (AVAi ≤0.6 cm²/m², MG ≥ 40 mm Hg), discordant-severity-grading (DG) with low-MG (AVAi ≤0.6 cm(2)/m(2), MG <40 mm Hg), or high-MG (AVAi >0.6 cm(2)/m(2), MG ≥40 mm Hg).

RESULTS

The MG (discordant in 29%) was strongly determined by AVA and flow but also independently and strongly influenced by AVC-load (p < 0.0001) and systemic arterial compliance (p < 0.0001). The AVC-load (median [interquartile range]) was similar within patients with DG (low-MG: 1,619 [965 to 2,528] arbitrary units [AU]; high-MG: 1,736 [1,209 to 2,894] AU; p = 0.49), higher than CG-moderate-AS (861 [427 to 1,519] AU; p < 0.0001) but lower than CG-severe-AS (2,931 [1,924 to 4,292] AU; p < 0.0001). The AVC-load thresholds separating severe/moderate AS were defined in CG-AS with normal flow (stroke-volume-index >35 ml/m(2)). The AVC-load, absolute or indexed, identified severe AS accurately (area under the curve ≥0.89, sensitivity ≥86%, specificity ≥79%) in men and women. Upon application of these criteria to DG-low MG, at least one-half of the patients were identified as severe calcified aortic valve disease, irrespective of flow.

CONCLUSIONS

Among patients with AS, MG is often discordant from AVA and is determined by multiple factors, valvular (AVC) and non-valvular (arterial compliance) independently of flow. The AVC-load by MDCT, strongly associated with AS severity, allows diagnosis of severe calcified aortic valve disease. At least one-half of the patients with discordant low gradient present with heavy AVC-load reflective of severe calcified aortic valve disease, emphasizing the clinical yield of AVC quantification by MDCT to diagnose and manage these complex patients.

Regional annular geometry in patients with mitral regurgitation: implications for annuloplasty ring selection

BACKGROUND

The saddle shape of the normal mitral annulus has been quantitatively described by several groups. There is strong evidence that this shape is important to valve function. A more complete understanding of regional annular geometry in diseased valves may provide a more educated approach to annuloplasty ring selection and design. We hypothesized that mitral annular shape is markedly distorted in patients with diseased valves.

METHODS

Real-time 3-dimensional echocardiography was performed in 20 patients with normal mitral valves, 10 with ischemic mitral regurgitation, and 20 with myxomatous mitral regurgitation (MMR). Thirty-six annular points were defined to generate a 3-dimensional model of the annulus. Regional annular parameters were measured from these renderings. Left ventricular inner diameter was obtained from 2-dimensional echocardiographic images.

RESULTS

Annular geometry was significantly different among the three groups. The annuli were larger in the MMR and in the ischemic mitral regurgitation groups. The annular enlargement was greater and more pervasive in the MMR group. Both diseases were associated with annular flattening, although though the regional distribution of that flattening was different between groups. Left ventricular inner diameter was increased in both groups. However, relative to the Left ventricular inner diameter, the annulus was disproportionately dilated in the MMR group.

CONCLUSIONS

Patients with MMR and ischemic mitral regurgitation have enlarged and flattened annuli. In the case of MMR, annular distortions may be the driving factor leading to valve incompetence. These data suggest that the goal of annuloplasty should be the restoration of normal annular saddle shape and that the use of flexible, partial, and flat rings may be ill advised.

Selective heart rate reduction with ivabradine unloads the left ventricle in heart failure patients. J Am Coll Cardiol. 2013;62:1977-1985. [PMID: 23933545 DOI: 10.1016/j.jacc.2013.07.027]

OBJECTIVES

The study aimed to determine whether isolated heart rate (HR) reduction with ivabradine reduces afterload of patients with systolic heart failure.

BACKGROUND

The effective arterial elastance (Ea) represents resistive and pulsatile afterload of the heart derived from the pressure volume relation. HR modulates Ea, and, therefore, afterload burden.

METHODS

Among the patients with systolic heart failure (ejection fraction ≤35%) randomized to either placebo or ivabradine in the SHIFT (Systolic Heart Failure Treatment With the If Inhibitor Ivabradine Trial), 275 patients (n = 132, placebo; n = 143, ivabradine 7.5 mg twice a day) were included in the echocardiographic substudy. Ea, total arterial compliance (TAC), and end-systolic elastance (Ees) were calculated at baseline and after 8 months of treatment. Blood pressure was measured by arm cuff; stroke volume (SV), ejection fraction, and end-diastolic volume were assessed by echocardiography.

RESULTS

At baseline Ea, TAC, HR, and Ees did not differ significantly between ivabradine- and placebo-treated patients. After 8 months of treatment, HR was significantly reduced in the ivabradine group (p < 0.0001) and was accompanied by marked reduction in Ea (p < 0.0001) and improved TAC (p = 0.004) compared with placebo. Although contractility remained unchanged, ventricular-arterial coupling was markedly improved (p = 0.002), resulting in a higher SV (p < 0.0001) in the ivabradine-treated patients.

CONCLUSIONS

Isolated HR reduction by ivabradine improves TAC, thus reducing Ea. Because Ees is unaltered, improved ventricular-arterial coupling is responsible for increased SV. Therefore, unloading of the heart may contribute to the beneficial effect of isolated HR reduction in patients with systolic heart failure.

Directed epicardial assistance in ischemic cardiomyopathy: flow and function using cardiac magnetic resonance imaging

BACKGROUND

Heart failure after myocardial infarction (MI) is a result of increased myocardial workload, adverse left ventricular (LV) geometric remodeling, and less efficient LV fluid movement. In this study we utilize cardiac magnetic resonance imaging to evaluate ventricular function and flow after placement of a novel directed epicardial assist device.

METHODS

Five swine underwent posterolateral MI and were allowed to remodel for 12 weeks. An inflatable bladder was positioned centrally within the infarct and secured with mesh. The device was connected to an external gas exchange pump, which inflated and deflated in synchrony with the cardiac cycle. Animals then underwent cardiac magnetic resonance imaging during active epicardial assistance and with no assistance.

RESULTS

Active epicardial assistance of the infarct showed immediate improvement in LV function and intraventricular flow. Ejection fraction significantly improved from 26.0% ± 4.9% to 37.3% ± 4.5% (p < 0.01). End-systolic volume (85.5 ± 12.7 mL versus 70.1 ± 11.9 mL, p < 0.01) and stroke volume (28.5 ± 4.4 mL versus 39.9 ± 3.1 mL, p = 0.03) were also improved with assistance. End-diastolic volume and regurgitant fraction did not change with treatment. Regional LV flow improved both qualitatively and quantitatively during assistance. Unassisted infarct regional flow showed highly discoordinate blood movement with very slow egress from the posterolateral wall. Large areas of stagnant flow were also identified. With assistance, posterolateral wall blood velocities improved significantly during both systole (26.4% ± 3.2% versus 12.6% ± 1.2% maximum velocity; p < 0.001) and diastole (54.3% ± 9.3% versus 24.2% ± 2.5% maximum velocity; p < 0.01).

CONCLUSIONS

Directed epicardial assistance can improve LV function and flow in ischemic cardiomyopathy. This novel device may provide a valuable alternative to currently available heart failure therapies.

Ventricular-arterial coupling, remodeling, and prognosis in chronic heart failure

OBJECTIVES

The objective of this study was to compare the physiological determinants of ejection fraction (EF)-ventricular size, contractile function, and ventricular-arterial (VA) interaction-and their associations with clinical outcomes in chronic heart failure (HF).

BACKGROUND

EF is a potent predictor of HF outcomes, but represents a complex summary measure that integrates several components including left ventricular size, contractile function, and VA coupling. The relative importance of each of these parameters in determining prognosis is unknown.

METHODS

In 466 participants with chronic systolic HF, we derived quantitative echocardiographic measures of EF: cardiac size (end-diastolic volume [EDV]); contractile function (the end-systolic pressure volume relationship slope [Eessb] and intercept [V0]); and VA coupling (arterial elastance [Ea]/Eessb). We determined the association between these parameters and the following adverse outcomes: 1) the combined endpoint of death, cardiac transplantation, or ventricular assist device (VAD) placement; and 2) cardiac hospitalization.

RESULTS

Over a median follow-up of 3.4 years, there were 76 deaths, 52 transplantations, 14 VAD placements, and 684 cardiac hospitalizations. EF was independently associated with death, transplantation, and VAD placement (adjusted hazard ratio [HR]: 3.0; 95% confidence interval [CI]: 1.8 to 5.0 comparing third and first tertiles), as were EDV (HR: 2.6; 95% CI: 1.5 to 4.2); V0 (HR: 3.6; 95% CI: 2.1 to 6.1); and Ea/Eessb (HR: 2.1; 95% CI: 1.3 to 3.3). EDV, V0, and Ea/Eessb were also associated with risk of cardiac hospitalization. Eessb was not significantly associated with any adverse outcomes in adjusted analyses.

CONCLUSIONS

Left ventricular size, V0, and VA coupling are associated with prognosis in systolic HF, but end-systolic elastance (Eessb) is not. Assessment of VA coupling via Ea/Eessb is an additional noninvasively derived metric that can be used to gauge prognosis in human HF.