Congestive heart failure: treat the disease, not the symptom--return to normalcy

Prioritizing symptom management in the treatment of chronic heart failure

Chronic heart failure (CHF) is a chronic, progressive disease that has detrimental consequences on a patient's quality of life (QoL). In part due to requirements for market access and licensing, the assessment of current and future treatments focuses on reducing mortality and hospitalizations. Few drugs are available principally for their symptomatic effect despite the fact that most patients' symptoms persist or worsen over time and an acceptance that the survival gains of modern therapies are mitigated by poorly controlled symptoms. Additional contributors to the failure to focus on symptoms could be the result of under‐reporting of symptoms by patients and carers and a reliance on insensitive symptomatic categories in which patients frequently remain despite additional therapies. Hence, formal symptom assessment tools, such as questionnaires, can be useful prompts to encourage more fidelity and reproducibility in the assessment of symptoms. This scoping review explores for the first time the assessment options and management of common symptoms in CHF with a focus on patient‐reported outcome tools. The integration of patient‐reported outcomes for symptom assessment into the routine of a CHF clinic could improve the monitoring of disease progression and QoL, especially following changes in treatment or intervention with a targeted symptom approach expected to improve QoL and patient outcomes.

Echocardiographic Predictors of Long-Term Survival in Patients Undergoing Cardiac Resynchronization Therapy: What Is the Optimal Metric?

BACKGROUND

Multiple definitions of reverse ventricular remodeling (RVR) employing various changes in left ventricular end-systolic (LVESV) or diastolic volumes (LVEDVs) or left ventricular ejection fraction (LVEF) have been used in determining cardiac resynchronization therapy (CRT) response, making comparability across studies difficult. We compared different metrics to each other, and in combination, in terms of association with long-term outcomes.

METHODS

We collected clinical and echocardiographic data on 436 patients undergoing CRT. LVEF was assessed via a combined volumetric and visual assessment. Volumes were manually traced. Using a nested multivariate model of a priori determined predictors of long-term survival free of left ventricular assist device (LVAD) or heart transplant, multiple definitions of RVR were added to the model individually to determine which provided the best model fit.

RESULTS

Over a mean follow-up of 5.4 ± 2.3 years, there were 198 endpoints (10 LVADs, 15 heart transplants, and 173 deaths). When added to a nested model controlling for multiple potential confounders, all definitions of RVR were significantly associated with improved survival. Changes in LVEF and LVESV were superior to changes in LVEDV. A combination metric of an LVEF improvement ≥ 5% and LVESV reduction ≥ 10% was the best overall metric for model fit.

CONCLUSIONS

Changes in LVESV and LVEF are better predictors of long-term outcome following CRT compared to changes in LVEDV. Adding an assessment of LVEF to reduction in LVESV ≥ 10% provided the best overall definition for RVR in predicting CRT outcomes.

Left Ventricular Aneurysmectomy: Tailored Scar Excision and Linear Closure

Coronary artery bypass surgery with or without aneurysmectomy is used to treat patients with left ventricular aneurysm. There is debate about patient selection and the appropriate surgical technique. We analyzed the results of 102 consecutive patients who underwent left ventricular aneurysmectomy and reconstruction using a modified linear closure technique between 1992 and 2003. The mean age was 62 years, 81% of the patients were male, and 47% had an ejection fraction < 35%. The locations of the left ventricular aneurysms were anteroapical (75%), apical (21%), and posteroinferior (4%); 23% contained thrombi. Additional procedures included aortic valve replacement in 4, mitral valve repair in 1, and coronary bypass grafting in 98 patients; 3 underwent isolated repair of left ventricular aneurysm. Hospital mortality was 7% and long-term survival was 76% at a mean follow-up of 39 months. Most patients improved symptomatically postoperatively. Left ventricular aneurysm repair with tailored scar excision and a modified closure technique is associated with acceptable mortality and long-term survival.

Exploring Guidelines for Classification of Major Heart Failure Subtypes by Using Machine Learning

BACKGROUND

Heart failure (HF) manifests as at least two subtypes. The current paradigm distinguishes the two by using both the metric ejection fraction (EF) and a constraint for end-diastolic volume. About half of all HF patients exhibit preserved EF. In contrast, the classical type of HF shows a reduced EF. Common practice sets the cut-off point often at or near EF = 50%, thus defining a linear divider. However, a rationale for this safe choice is lacking, while the assumption regarding applicability of strict linearity has not been justified. Additionally, some studies opt for eliminating patients from consideration for HF if 40 < EF < 50% (gray zone). Thus, there is a need for documented classification guidelines, solving gray zone ambiguity and formulating crisp delineation of transitions between phenotypes.

METHODS

Machine learning (ML) models are applied to classify HF subtypes within the ventricular volume domain, rather than by the single use of EF. Various ML models, both unsupervised and supervised, are employed to establish a foundation for classification. Data regarding 48 HF patients are employed as training set for subsequent classification of Monte Carlo-generated surrogate HF patients (n = 403). Next, we map consequences when EF cut-off differs from 50% (as proposed for women) and analyze HF candidates not covered by current rules.

RESULTS

The training set yields best results for the Support Vector Machine method (test error 4.06%), covers the gray zone, and other clinically relevant HF candidates. End-systolic volume (ESV) emerges as a logical discriminator rather than EF as in the prevailing paradigm.

CONCLUSIONS

Selected ML models offer promise for classifying HF patients (including the gray zone), when driven by ventricular volume data. ML analysis indicates that ESV has a role in the development of guidelines to parse HF subtypes. The documented curvilinear relationship between EF and ESV suggests that the assumption concerning a linear EF divider may not be of general utility over the complete clinically relevant range.

Characterizing heart failure in the ventricular volume domain

Heart failure (HF) may be accompanied by considerable alterations of left ventricular (LV) volume, depending on the particular phenotype. Two major types of HF have been identified, although heterogeneity within each category may be considerable. All variants of HF show substantially elevated LV filling pressures, which tend to induce changes in LV size and shape. Yet, one type of HF is characterized by near-normal values for LV end-diastolic volume (EDV) and even a smaller end-systolic volume (ESV) than in matched groups of persons without cardiac disease. Furthermore, accumulating evidence indicates that, both in terms of shape and size, in men and women, the heart reacts differently to adaptive stimuli as well as to certain pharmacological interventions. Adjustments of ESV and EDV such as in HF patients are associated with (reverse) remodeling mechanisms. Therefore, it is logical to analyze HF subtypes in a graphical representation that relates ESV to EDV. Following this route, one may expect that the two major phenotypes of HF are identified as distinct entities localized in different areas of the LV volume domain. The precise coordinates of this position imply unique characteristics in terms of the actual operating point for LV volume regulation. Evidently, ejection fraction (EF; equal to 1 minus the ratio of ESV and EDV) carries little information within the LV volume representation. Thus far, classification of HF is based on information regarding EF combined with EDV. Our analysis shows that ESV in the two HF groups follows different patterns in dependency of EDV. This observation suggests that a superior HF classification system should primarily be founded on information embodied by ESV.

Left-ventricular aneurysms: from disease to repair

Myocardial infarction may be complicated by the formation of a left-ventricular aneurysm that distorts the normal elliptical geometry of the ventricle to produce a dilated spherical ventricle with limited contractile and filling capacities. One of the consequences is congestive heart failure, which may be refractory to medical therapy and require surgical treatment. Surgical methods to restore the volume and shape of the left ventricle have evolved over the years. Nevertheless, although surgery for left-ventricular aneurysms has been performed for almost 50 years, the most appropriate approach is still controversial. This review gives an overview of the postinfarction left-ventricular aneurysm, tackling issues from the disease itself to surgical and other techniques of ventricular remodeling.

Decision support in surgical management of ischemic cardiomyopathy

OBJECTIVES

The surgical approach to ischemic cardiomyopathy maximizing survival remains a dilemma, with decisions complicated by secondary mitral regurgitation, ventricular remodeling, and heart failure. As a component of decision support, we sought to develop prediction models for comparing survival after coronary artery bypass grafting alone, coronary artery bypass grafting plus mitral valve anuloplasty, coronary artery bypass grafting plus surgical ventricular restoration, and listing for cardiac transplantation.

METHODS

From 1997 to 2007, 1468 patients with ischemic cardiomyopathy (ejection fraction <30%) underwent coronary artery bypass grafting alone (n = 386), coronary artery bypass grafting plus mitral valve anuloplasty (n = 212), coronary artery bypass grafting plus surgical ventricular restoration (n = 360), or listing for cardiac transplantation (n = 510). Mean follow-up was 3.8 +/- 2.8 years, with 5577 patient-years of data available for analysis. Risk factors were identified for early and late mortality by using 80% training and 20% validation sets. Outcomes were calculated for each applicable strategy to identify which maximized predicted 5-year survival. Models were programmed as a strategic decision-support tool.

RESULTS

One-, 5-, and 9-year survival were as follows, respectively: coronary artery bypass grafting, 92%, 72%, and 53%; coronary artery bypass grafting plus mitral valve anuloplasty, 88%, 57%, and 34%; coronary artery bypass grafting plus surgical ventricular restoration, 94%, 76%, and 55%; and listing for cardiac transplantation, 79%, 66%, and 54%. Risk factors included older age, higher New York Heart Association class, lower ejection fraction, longer interval from myocardial infarction to operation, and numerous comorbidities. Predicted and observed survivals in validation groups were similar (P > .1). Patient-specific simultaneous solutions of applicable models revealed therapy potentially providing maximum survival benefit. Coronary artery bypass grafting alone and listing for cardiac transplantation often maximized 5-year survival; only 15% of patients undergoing coronary artery bypass grafting plus mitral valve anuloplasty were predicted to fare best with this therapy.

CONCLUSION

Validated prediction models can aid surgeons in recommending personalized treatment plans that maximize short- and long-term survival for ischemic cardiomyopathy.

Patch size, shape and orientation affect geometrical outcomes of surgical anterior ventricular restoration

OBJECTIVES

To verify whether the use of a small, oval-shaped patch limits the trend toward re-dilatation compared to endoventricular circular patch plasty and leads to different geometrical and functional results in surgical anterior restoration.

METHODS

Thirty-seven patients with ischemic cardiomyopathy after anterior myocardial infarction end-systolic volume index of > or =45 ml/m2, ejection fraction of < or =35%, and no combined mitral procedures, underwent surgical anterior ventricular restoration between January 2000 and April 2003: 18 patients (group 1) were operated on using the endoventricular circular patch plasty technique (mean patch area 9.6 cm2) and 19 patients (group 2) received a small, obliquely oriented, oval-shaped patch (mean patch area 6.2 cm2). Ten geometrical parameters were studied preoperatively and at least 6 and 12 months after surgery. Data were analyzed using repeated-measures ANOVA, chi2, paired and unpaired Student's t-test, and binary logistic regression.

RESULTS

Group 1 showed a worsening over time in systolic and diastolic longitudinal length, end-diastolic volume (P < 0.001), end-diastolic volume index (P = 0.006), end-systolic volume (P = 0.005), and end-systolic volume index (P = 0.03). Group 2 showed an improvement in percentage of akinesia and wall motion score index (P < 0.001) and a worsening only in end-systolic diameter (P = 0.03) and end-diastolic volume (P = 0.04). At 12-month follow-up, ANOVA revealed that the oval patch positively influenced end-diastolic volume (P = 0.03), end-systolic volume (P = 0.03), and end-systolic volume index (P = 0.05), and group 2 had a significantly higher number of patients with an end-systolic volume index of <45 ml/m2 (P = 0.01).

CONCLUSION

The use of a small, narrow, obliquely oriented, oval patch may help to prevent adverse ventricular remodeling over time.

Predicting Operative Mortality After Surgery for Ischemic Cardiomyopathy

BACKGROUND

Ischemic cardiomyopathy accounts for as many as 70% of cases of heart failure with no clear algorithm for the treatment. We assessed the operative risks and mortality of various surgical options: coronary artery bypass grafting (CABG), CABG and mitral valve repair (CABG/MVR), and left ventricular remodeling (LVR) with or without CABG. We hypothesized that additional procedures increased the operative risk. We determined whether preoperative variables (eg, urgency of operation) impacted the surgical outcome.

METHODS

A retrospective analysis of University of Virginia patients from January 2000 until September 2006 was undertaken. Patients with CABG and an ejection fraction less than 35%, ischemic mitral regurgitation by operative characterization, and patients with LVR were identified. The Society of Thoracic Surgeons database risks, complications, and outcomes as well as degree of revascularization, quality of targets, and type of additional procedures were analyzed. Incomplete revascularization was defined as a planned bypass not performed. Poor targets were defined as per the operative note.

RESULTS

In all, 382 patients were identified (220 CABG, 97 CABG/MVR, and 65 LVR). The overall operative mortality was 7.9%. Mortality was 9.1% for CABG, 8.2% for CABG/MVR, and 3.1% for LVR. Preoperative risk factors for mortality included diabetes mellitus (p = 0.05), previous cerebrovascular disease (p = 0.05), and chronic renal dysfunction (p = 0.03). Patients with emergency operations had a significantly increased mortality (p < 0.001) as did patients with intra-aortic balloon pumps (p = 0.015).

CONCLUSIONS

Additional procedures such as MVR or LVR did not add to the operative risk of CABG for ischemic cardiomyopathy. Only preoperative comorbidities and emergency operations increased operative mortality.

Left ventricle remodelling by double-patch sandwich technique

Background

The sandwich double-patch technique was adopted as an alternative method for reconstruction of the left ventricle after excision of postinfarction dysfunctional myocardium to solve technical problems due to the thick edges of the ventricular wall.

Methods

Over a 5-year period, 12 of 21 patients with postinfarction antero-apical left ventricular aneurysm had thick wall edges after wall excision. It was due to akinetic muscular thick tissue in 6 cases, while in the other 6 with classic fibrous aneurysm, thick edges remained after the cut of the border zone. The ventricular opening was sandwiched between two patches and this is a technique which is currently used for the treatment of the interventricular septum rupture. In our patients the patches are much smaller than the removed aneurysm and they were sutured simply by a single row of single stitches. However, in contrast to interventricular septum rupture where the patches loosen the tension of the tissues, in our patients the patches pull strongly and restrain the walls by fastening their edges and supporting tight stitches. In this way they could narrow the cavity and close the ventricle.

Results

The resected area varied from 5 × 4 to 8 × 8 cm. Excision was extended into the interventricular septum in 5 patients, thus opening the right ventricle. CABG was performed on all patients but two. Left ventricular volumes and the ejection fraction changed significantly: end-systolic volume 93.5 ± 12.4 to 57.8 ± 8.9 ml, p < 0.001; end-diastolic volume 157.2 ± 16.7 to 115.3 ± 14.9 ml, p < 0.001; ejection fraction 40.3 ± 4.2 to 49.5 ± 5.7%, p < 0.001. All patients did well. One patient suffered from bleeding, which was not from the wall suture, and another had a left arm paresis. The post-operative hospital stay was 5 to 30 days with a mean 10.5 ± 7.5 days/patient. At follow-up, 9 to 60 months mean 34, all patients were symptom-free. NYHA class 2.5 ± 0.8 changed to 1.2 ± 0.4, p < 0.001.

Conclusion

The double-patch sandwich technique (bi-patch closure) offers some advantages and does not result in increased morbidity and mortality. In the case of excising a left ventricular aneurysm, this technique in no way requires eversion of the edges, felt strips, buttressed and multiple sutures, all of which are needed for longitudinal linear closure. Moreover, it does not require purse string sutures, endocardial scar remnant to secure the patch or folding the excluded non-functional tissue, all of which are needed for endoventricular patch repair.

Effects of Surgical Ventricular Restoration on Left Ventricular Function: Dynamic MR Imaging

PURPOSE

To retrospectively evaluate with dynamic magnetic resonance (MR) imaging the changes in global and regional left ventricular (LV) function after surgical ventricular restoration (SVR) performed in chronic ischemic heart disease patients with large nonaneurysmal or aneurysmal postmyocardial infarction zones.

MATERIALS AND METHODS

The study was performed with institutional review board approval, and a waiver of individual informed consent was obtained. The study was HIPAA compliant. Patients (83 men, 22 women; mean age, 61 years +/- 9 [standard deviation]) were evaluated with MR imaging before and after SVR as follows: pre-SVR examination (n = 105; 25 days +/- 39 before SVR; median, 7 days; range, 1-189 days), early post-SVR examination (n = 95, 7 days +/- 3 after SVR), and late post-SVR (n = 35, 313 days +/- 158 after SVR). Cine MR imaging allowed calculation of ejection fraction and rate-corrected velocity of circumferential fiber shortening (Vcf(C)) for global LV functional evaluation, whereas tagged MR imaging (spatial modulation of magnetization with harmonic phase analysis) permitted assessment of regional circumferential strain (E(C)) with coronary distribution. Vcf(C) and E(C) were computed at both LV base- and mid-LV short-axis levels remote from the site of anteroapical SVR.

RESULTS

Prior to SVR, LV dilatation and diminished global and regional LV function were observed. At early post-SVR examination, Vcf(C) had improved significantly but E(C) showed a worsening trend overall, although only E(C )of the right coronary artery at the mid-LV level worsened significantly. At late post-SVR examination, Vcf(C) values were improved when compared with pre-SVR values, although E(C) showed no statistically significant improvement. When compared with that at early post-SVR examination, however, E(C) showed significant improvement in two segments: left anterior descending artery and right coronary artery at mid-LV level.

CONCLUSION

Although volume-based indexes of global LV function improve significantly after SVR, regional LV function did not improve significantly; there was evidence of continued LV remodeling after SVR.

A new shape for an old function: lasting effect of a physiologic surgical restoration of the left ventricle

BACKGROUND

Long-term morphofunctional outcome may vary widely in surgical anterior left ventricular wall restoration, suggesting variability in post-surgical remodeling similar to that observed following acute myocardial infarction. The aim of this pilot study was to demonstrate that surgical restoration obtained with a particular shape of endoventricular patch leads to steady morphofunctional ventricular improvement when geometry, volume and residual akinesia can be restored as normal as possible.

METHODS

This study involved 12 consecutive patients with previous anterior myocardial infarction, dilated cardiomyopathy and no mitral procedures, who underwent left ventricular reconstruction and coronary revascularization between May 2002 and May 2003 using a small, narrow, oval patch aiming at a volume <or= 45 mL/m2 with elliptical shape. Eleven geometric parameters were examined preoperatively and at least 3, 12 and 24 months after the operation by serial echocardiographic studies and evaluated by paired t test taking the time of surgery as a starting point for remodeling.

RESULTS

All patients were in NYHA class 1 at follow-up. Patch geometry obtained a conical shape of the ventricle with new apex, physiologic rearrangement of functioning myocardial wall and small residual akinesia. Ventricular changes at the four time-points showed that all parameters improved significantly compared to preoperative values (end-diastolic volume = 184.2 +/- 23.9 vs 139.9 +/- 22.0, p = 0.001; vs 151.0 +/- 33.8, p = 0.06; vs 144.9 +/- 34.0, p = 0.38; end-systolic volume = 125.7 +/- 20.6 vs 75.2 +/- 14.1, p = 0.001; vs 82.1 +/- 23.9, p = 0,18; vs 77.1 +/- 19.4, p = 0.41) without further changes during follow-up except for wall motion score index (2.0 +/- 0.2 to 1.7 +/- 0.2, to 1.4 +/- 0.2, to 1.3 +/- 0.2) and percentage of akinesia (30.4 +/- 7.5 to 29.3 +/- 4.2, to 19.8 +/- 11.6, to 14.5 +/- 7.2) which slowly and significantly improved suggesting a positive post-surgery remodeling.

CONCLUSION

Ventricular reconstruction caring of physiological shape, volume, revascularization and residual akinesia obtained a steady geometry. Positive remodeling and equalization of geometrical outcome may persistently prevent long-term redilation.

Myocardial protection in the failing heart: I. Effect of cardioplegia and the beating state under simulated left ventricular restoration

OBJECTIVE

Heart failure was induced by cardiac pacing to evaluate myocardial flow distribution of the open ventricle during delivery of either cardioplegia or in the beating state during simulated left ventricular restoration.

METHODS

Studies included 5 (pacing-induced) failing pig hearts and 6 control hearts. Pacing-induced cardiac failure reduced fractional shortening by approximately 22%, increased left ventricular end-diastolic diameter by 34%, caused pulmonary hypertension (mean blood pressure increased from 12 to 35 mm Hg), and led to significant ascites. Global and regional coronary blood flow were measured with microspheres during cardiopulmonary bypass at 80 mm Hg perfusion pressure in either vented (collapsed) or open (exposure by traction for left ventricular restoration) left ventricles during continuous perfusion under either beating-heart or cardioplegic conditions.

RESULTS

In control hearts, venting and exposure ventriculotomy did not affect flow. In failing hearts decompressed by venting, coronary flow was lower during the beating and cardioplegic delivery than during control conditions at the same perfusion pressure of 80 mm Hg. Mean cardioplegic flow during ventricular decompression by venting exceeded beating flow by 97%. Conversely, traction to increase the ventricular radius during exposure ventriculotomy reduced endocardial cardioplegic coronary blood flow by 64% (from 0.97 to 0.59 mL/[min x g]), whereas the beating state raised endocardial flow by 95% (from 0.40 to 0.78 mL/[min x g]). Changing ventricular shape changed coronary vascular resistance in failing hearts during beating or cardioplegic delivery.

CONCLUSIONS

Coronary blood flow alterations occurred only in failing hearts when geometry was changed from closed to open state. The beating method provided more endocardial flow than cardioplegic delivery during ventricular exposure for restoration. Vascular remodeling raised coronary vascular resistance in failing hearts, thereby requiring higher pressure for similar blood flows.

Surgical ventricular reverse remodeling in severe ischemic dilated cardiomyopathy: the relevance of the left ventricular equator as a prognostic factor

OBJECTIVES

Surgical ventricular reverse remodeling has been shown to possibly improve hemodynamics and symptoms, but effects on long-term mortality are not established. No consistent data are available on which patients will benefit most from this procedure. This study was designed to analyze the predictors of long-term survival after surgical ventricular reverse remodeling in patients with ischemic cardiomyopathy.

METHODS

Eighty-five patients who underwent surgical ventricular reverse remodeling between May 1991 and October 2003 were retrospectively analyzed. Left ventricular wall motion and left ventricular equatorial diameter were assessed by means of angioventriculography. Left ventricular ejection fraction and volumes were measured by means of echocardiography. Cox regression analysis was used in several combinations to create a final model for identifying predictors of death.

RESULTS

Actuarial survival after 1, 3, 5, and 10 years was 89%, 79%, 75%, and 75%, respectively. New York Heart Association class improved from 2.9 +/- 1.0 to 1.3 +/- 0.5 (P < .0001), left ventricular ejection fraction increased from 27.6% +/- 6.3% to 43.0% +/- 10.1% (P < .0001), and left ventricular end-systolic volume index decreased from 89.6 +/- 27.6 mL/m2 to 56.5 +/- 34.5 mL/m2 (P < .0001). Multivariate analysis identified left ventricular equatorial diameter of 70 mm or greater (hazard ratio, 5.28; 95% confidence interval, 1.79-11.71; P = .020) and segmental akinesia (hazard ratio, 4.46; 95% confidence interval, 1.23-17.12; P = .024) as the only independent predictors of death.

CONCLUSIONS

In this analysis of a single cohort of patients, surgical ventricular reverse remodeling improves the symptoms of ischemic cardiomyopathy, as well as left ventricular function, shape, and volume, with encouraging long-term outcomes, particularly in patients with dyskinesia. A left ventricular equatorial diameter of 70 mm or greater appears to be an important independent prognostic factor, which suggests the relevance of the left ventricular equatorial region for effective surgical reverse remodeling.

Tissue-engineered myocardial patch derived from extracellular matrix provides regional mechanical function

BACKGROUND

Extracellular matrix (ECM), a tissue-engineered scaffold, recently demonstrated cardiomyocyte population after myocardial implantation. Surgical restoration of myocardium frequently uses Dacron as a myocardial patch. We hypothesized that an ECM-derived myocardial patch would provide a mechanical benefit not seen with Dacron.

METHODS AND RESULTS

Using a canine model, a full thickness defect in the right ventricle was repaired with either Dacron or ECM. A third group had no surgery and determined baseline RV function. Eight weeks later, global systolic function was assessed by the preload recruitable stroke work relationship. Regional systolic function was measured by systolic area contraction (SAC), calculated by high density mechanical mapping. Tau was used to assess global diastolic function. Recoil rate and diastolic shear were used as measures of regional diastolic function. After functional data acquisition, tissue was fixed for histological evaluation. Global systolic and diastolic functions were similar at baseline and after ECM and Dacron implantation. Regional systolic function was greater in the ECM group compared with the Dacron group (SAC: 4.1+/-0.9% versus -1.8+/-1.1, P<0.05). Regional diastolic function was also greater in the ECM group (recoil rate (degrees sec(-1)): -44+/-7 versus -17+/-2, ECM versus Dacron; P<0.05). Immunohistochemical analysis revealed cardiomyocytes in the ECM implant region, a finding not seen with Dacron.

CONCLUSIONS

At 8 weeks, an ECM-derived tissue-engineered myocardial patch provides regional mechanical function, likely related to cardiomyocyte population. These results are in sharp contrast to Dacron, a commonly used myocardial patch.

Surgical ventricular restoration in end-stage ischemic cardiomyopathy patients

BACKGROUND

Surgical ventricular restoration (SVR) has generally been contraindicated in patients with an ejection fraction (EF) <20%, with pulmonary arterial (PA) pressure >60 mm Hg, and being treated with inotropic agents.

PATIENTS AND METHODS

The patients in this study were 6 men and 5 women 50 to 78 years of age (mean, 62.4 years). Three patients were in New York Heart Association (NYHA) class III with an EF <30%. Eight patients were in NYHA class IV with EF <20%, PA pressure >70 mm Hg, and left ventricular asynergy. Three patients had had recent myocardial infarction (MI) with shock and multiple organ failure. Three patients had mitral regurgitation, 1 patient had ventricular septal defect (VSD), 4 patients had diabetes mellitus, and 5 had morbid obesity. All patients underwent intraoperative transesophageal echocardiography and were being treated with milrinone or nesiritide. Seven patients had intraaortic balloon pumps. All patients underwent coronary artery bypass (CAB), receiving 1 to 5 (average, 3.54) grafts per patient. The SVR (Dor) procedure was performed with a Chase Mannequin device. Preoperative end-diastolic volume was 240 to 330 mL, and postoperative volume decreased to 110 to 130 mL. Two patients underwent mitral valve repair, and 1 underwent VSD closure. One patient underwent microwave ablation for atrial fibrillation.

RESULTS

Ten (91%) of 11 patients were discharged home in 10 to 14 days. There was 1 death: A 78-year-old man with acute MI died 43 days later of septic shock due to hemodialysis.

CONCLUSION

End-stage ischemic cardiomyopathy patients with EF <20% can safely undergo surgery after meticulous preoperative preparation to decrease PA pressure, pulmonary capillary wedge pressure, and peripheral vascular resistance and to increase CO by SVR, CAB, and correction of associated lesions. Mortality was 9% with improved hemodynamics and relief of congestive heart failure in all survivors for 3 to 12 months.

Partial Support with a Centrifugal Left Ventricular Assist Device Reduces Myocardial Oxygen Consumption in Chronic, Ischemic Heart Failure

BACKGROUND

Left ventricular assist devices (LVAD) are increasingly used for heart failure (CHF); however, the level of optimal support has not been elucidated. We hypothesize that partial LVAD support in an ovine model of microinfarction-induced CHF significantly reduces left ventricular myocardial oxygen consumption (LVVO2).

METHODS AND RESULTS

Microembolization of the circumflex coronary artery was used to induce CHF in 5 sheep (ejection fraction 28 +/- 2%). Four months later, animals underwent implantation of a centrifugal LVAD. LVAD flow was incrementally increased from 0% (baseline) to 25%, 50%, and 75% support of the LV. LVVO2 and stroke work (SW) were calculated at each increment. At baseline, LVVO2 (microL/100 g LV/beat) measured 43.2 +/- 3.4. LVVO2 decreased to 26.5 +/- 8.2,* 20.3 +/- 8.9,* and 12.6 +/- 6.3* at 25%, 50%, and 75% support (*P < .05). SW (mm Hg/mL) measured 1933.0 +/- 275.7 at baseline and decreased to 1588.0 +/- 204.1, 1181.0 +/- 157.2,* and 764.5 +/- 171.7* at 25%, 50%, and 75% support. Cardiac output, heart rate, and left main coronary artery blood flow were unaffected with partial support.

CONCLUSION

Complete support with a centrifugal LVAD is not necessary for achieving significant reductions in LVVO2 . Partial support of as little as 25% significantly reduces LVVO2 in CHF through comparatively minor reductions in cardiac work. This is the first study to examine partial LVAD support in a CHF model.

Helical myofiber orientation after myocardial infarction and left ventricular surgical restoration in sheep

OBJECTIVES

It has been proposed that successful left ventricular surgical restoration should restore normal helical myofiber orientation. A magnetic resonance imaging technique, magnetic resonance diffusion tensor imaging, has been developed to measure myocyte orientation. By using magnetic resonance diffusion tensor imaging, this study tested the hypothesis that (1) myocyte orientation is altered after anteroapical myocardial infarction and (2) left ventricular surgical restoration restores normal helix angles.

METHODS

Thirteen sheep underwent anteroapical myocardial infarction (25% of left ventricular mass). Ten weeks later, animals underwent either aneurysm plication (n = 8) or sham operations (n = 5). Six weeks after this operation, hearts were excised, perfusion fixed in diastole, and underwent magnetic resonance diffusion tensor imaging. Hearts from normal sheep (n = 5) were also harvested and imaged. Primary eigenvectors of the diffusion tensors from magnetic resonance diffusion tensor imaging were resolved into helix angles relative to a local wall coordinate system. Transmural samples of the helix angles were compared at the border zone of the aneurysm or repair (or a comparable distance from the base in normal sheep), 1 cm below the valves, and halfway between.

RESULTS

The helical myofiber orientation did not change after myocardial infarction. However, aneurysm plication caused myofibers in the anterior border zone to rotate counterclockwise (-35.6 +/- 10.5 degrees , P = .028) and those in the lateral border zone to rotate clockwise (34.4 +/- 8.1 degrees , P = .031).

CONCLUSIONS

Surgical restoration alters myocyte orientation adjacent to the surgical repair. However, myofiber orientation is not abnormal after myocardial infarction, and thus surgical restoration techniques intent on restoring normal helix angles might not be warranted.

Surgical Ventricular Restoration: Technique and Outcomes

Surgical ventricular restoration is a surgical procedure developed in an attempt to reverse the negative remodeling that occurs following myocardial infarction. The goal of the procedure is to: 1) reduce the size and restore the normal elliptical shape of the heart; 2) perform a complete myocardial revascularization; and 3) repair any mitral insufficiency. This article will review the surgical procedure and describe outcomes achieved with surgical ventricular restoration.

Determinants of postinfarction remodeling affect outcome and left ventricular geometry after surgical treatment of ischemic cardiomyopathy

OBJECTIVE

To identify the effects of the time between myocardial infarction and surgery, the site of infarction, mitral involvement on ventricular geometry, and clinical outcome in the treatment of ischemic cardiomyopathy in patients with heart failure.

METHODS

Sixty-nine consecutive patients with ischemic cardiomyopathy, indexed end-systolic volume > or =50 mL/m(2), ejection fraction < or =35%, and heart failure underwent surgery 81.9 +/- 100.8 months after myocardial infarction, using different techniques of ventricular restoration. Thirteen geometric parameters were studied pre- and postoperatively. Paired and unpaired t tests and general linear model for multivariate analysis were used to analyze subgroups. Logistic regression and Kaplan-Meier survival curves with pairwise log-rank were used to correlate covariates to clinical outcome.

RESULTS

Longer time to surgery and posterior necrosis linearly correlated with higher left ventricular volumes (r(2) =.66) and diameters (r(2) =.40). High grade of mitral regurgitation was always present in posterior infarctions. Hospital mortality was 4.3%. Complicated postoperative course was predicted by mitral surgery (P =.004) and longer time to surgery (P =.04). Survival was significantly lower in the posterior infarction (P =.0002) and mitral surgery (P =.001) subgroups. At a mean follow-up of 1.9 +/- 1.3 years, functional status and geometrical restoration are influenced by the studied covariates.

CONCLUSIONS

Longer time to surgery after myocardial infarction, its posterior location, and significant mitral regurgitation can affect left ventricular remodeling, surgical restoration, and clinical outcome in patients with ischemic cardiomyopathy.

The beating heart approach is not necessary for the dor procedure

BACKGROUND

Ventricular reconstruction using the Dor technique has been demonstrated to improve outcome in patients with dilated left ventricles. It has been suggested that a beating heart approach improves ventricular function by allowing the surgeon to palpate that part of the ventricle to exclude.

METHODS

We performed a retrospective analysis of patients who underwent an endoventricular circular patch plasty (Dor procedure) between 1998 and 2001. All patients who received ventricular restoration, with or without revascularization or valve repair, were included in the analysis. Discrete left ventricular aneurysms were excluded. Patients were divided into two groups: group 1 (n = 15) underwent ventricular reconstruction with the beating heart technique, whereas group 2 (n = 38) underwent restoration with the aorta cross-clamped. Clinical and hemodynamic data were collected from medical records and computerized databases and compared between the two groups.

RESULTS

Fifty-three patients underwent endoventricular circular patch plasty. All patients had enlarged ventricles (echocardiogram demonstrating unidimensional end-diastolic diameter >/= 6.0 cm) and echocardiographic evidence of severe left ventricular dysfunction (mean ejection fraction: group 1 = 21.4%; group 2 = 23.4%). No operative mortalities occurred in either group and all patients were discharged home alive (mean postoperative hospital stay 8.3 days [6 to 22 days]). All patients had improvement in left ventricular function with mean postoperative left ventricular ejection fraction of 36.9% (25% to 52%) in group 1 versus 38.1% (31% to 50%) in group 2, p = 0.081. Ventricular arrhythmias occurred in 5 of 15 group 1 patients and in 9 of 38 group 2 patients. Two patients in the entire cohort (1 patient in group 1, and 1 patient in group 2) had at least one readmission within 12 months with evidence of heart failure. The group 1 patient went on to successful transplant 11 months later, whereas the group 2 patient died 10 months later.

CONCLUSIONS

These results demonstrate that the Dor technique of ventricular restoration significantly improves left ventricular function and the beating heart approach provides no additional advantage over continuous aortic cross clamping.

The outcome and criteria for mitral valve surgery in patients with ischemic mitral regurgitation

OBJECTIVES

Mitral valve surgery for the correction of mitral regurgitation (MR) in patients with ischemic heart disease has been associated with poor prognosis. The criteria for selecting an appropriate surgical procedure are not clearly defined. The objectives of this study were to clarify the criteria for mitral valve manipulation and the outcome in patients with ischemic MR.

METHODS

Twenty patients with ischemic MR were proposed for surgery. Ten of them (group A) had grade II MR and underwent isolated coronary artery bypass grafting (CABG). The remaining 10 patients with grade III or more MR underwent both CABG and mitral valve repair (group B). Postoperative left ventricular function and outcome were compared.

RESULTS

Preoperative left ventricular end-systolic volume index (LVESVI) in group A was significantly smaller, while preoperative ejection fraction (EF) was almost equal between the groups. EF demonstrated a significant improvement in group A postoperatively, but no changes in group B. Two of group B died following surgery. The other patients were successfully treated with surgery which diminished MR. Congestive heart failure (CHF) developed in 2 patients of group B during follow-up and in none of group A. The 5-year freedom from CHF and the 5-year survival rate in group A were significantly greater than those in group B.

CONCLUSIONS

Deterioration of mitral valve function, which necessitated mitral valve repair, was more frequent in the impaired and enlarged hearts. Although mitral repair was beneficial for diminishing MR and New York Heart Association, postoperative course in patients with ischemic MR depended on the preoperative LVESVI.

Factors affecting late survival after surgical remodeling of left ventricular aneurysms

OBJECTIVES

Surgical remodeling of the left ventricle has involved various techniques of volume reduction. This study evaluates factors that influence long-term survival results with 3 operative methods.

METHODS

From 1979 to 2000, 157 patients (134 men, mean age 61 years) underwent operations for class III or IV congestive heart failure, angina, ventricular tachyarrhythmia, and sudden death after anteroseptal myocardial infarction. The preoperative ejection fraction was 28% +/- 0.9% (mean +/- standard error), and the pulmonary artery occlusive pressure was 15 +/- 0.07 mm Hg. Cardiogenic shock was present in 26 patients (16%), and an intra-aortic balloon pump was used in 48 patients (30%). The type of procedure depended on the extent of endocardial disease and was aimed at maintaining the ellipsoid shape of the left ventricle cavity. In group I patients (n = 65), radical aneurysm resection and linear closure were performed. In group II patients (n = 70), septal dyskinesis was reinforced with a patch (septoplasty). In group III patients (n = 22), ventriculotomy closure was performed with an intracavitary oval patch.

RESULTS

Hospital mortality was 16% (25/157) and was similar among the groups. Actuarial survival up to 18 years was better with a preoperative ejection fraction of 26% or greater (P =.004) and a pulmonary artery occlusive pressure of 17 mm Hg or less (P =.05). Survival was worse in patients who had intra-aortic balloon pump support (P =.03). Five-year survival for all patients in group III was higher than for patients in group II (67% vs 47%, P =.04).

CONCLUSIONS

Factors that improved long-term survival after left ventricular surgical remodeling were intraventricular patch repair, preoperative ejection fraction of 26% or greater, and pulmonary artery occlusive pressure of 17 mm Hg or less without the need for balloon pump assist.

A Model Incorporating Some of the Mechanical and Biochemical Factors Underlying Clot Formation and Dissolution in Flowing Blood

Multiple interacting mechanisms control the formation and dissolution of clots to maintain blood in a state of delicate balance. In addition to a myriad of biochemical reactions, rheological factors also play a crucial role in modulating the response of blood to external stimuli. To date, a comprehensive model for clot formation and dissolution, that takes into account the biochemical, medical and rheological factors, has not been put into place, the existing models emphasizing either one or the other of the factors. In this paper, after discussing the various biochemical, physiologic and rheological factors at some length, we develop a model for clot formation and dissolution that incorporates many of the relevant crucial factors that have a bearing on the problem. The model, though just a first step towards understanding a complex phenomenon, goes further than previous models in integrating the biochemical, physiologic and rheological factors that come into play.

Repair of postinfarction dyskinetic LV aneurysm with either linear or patch technique

OBJECTIVES

Controversy still exists regarding the optimal surgical technique for postinfarction dyskinetic left ventricular aneurysm (LVA) repair. We compared the efficacy of two established techniques, linear vs. patch remodeling, for repair of dyskinetic LVA.

PATIENTS AND METHODS

From 1989 to 1998, 95 (16 women, 79 men) consecutive patients were operated on for postinfarction dyskinetic LVA. Thirty-four patients underwent patch remodeling (R) and 61 linear (L) repair. The mean age was 61.1+/-8.5 years. Indications for surgery alone or in combination included angina in 72 patients, dyspnea in 64 and ventricular tachycardia in 41. Thirty-seven patients had a history of congestive heart failure (R 13 (38%), L 24 (39%), NS). The mean ejection fraction (EF) with aneurysm was 0.29+/-0.09 in R vs. 0.35+/-0.10 in L (P<0.04), whereas the mean EF without aneurysm was 0.43+/-0.11 in R vs. 0.46+/-0.08 in L (P=0.3). Seventy-one aneurysms were anterior (R 30 (88%), L 41 (68%), P<0.05). Concomitant coronary artery bypass grafting was performed in 84 patients (R 29 (85%), L 55 (90%), NS). Follow-up ranged from 1 to 12 years (mean 5.6+/-3.4 years, median 6.1 years).

RESULTS

Early mortality was 8% (n=8) (R 4, L 4, NS). Survival at 1, 5 and 10 years was 88, 73, and 44%, respectively. It did not differ significantly between R (1 and 5 year survival 85, 66%) and L (90, 76%, P=0.58). Preoperative risk factors for mortality were history of congestive heart failure (1 and 5 year survival 81 and 57% vs. 90 and 78%, respectively, hazard ratio (HR)=1.95, P<0.05), non-anterior localization of the aneurysm (86 and 49% vs. 86 and 77%, HR=2.06, P<0.05), history of thromboembolic events (57 and 19% vs. 89 and 74%, HR=3.27, P<0.05), and left ventricular EF (HR=0.97 per %, P=0.05). At late follow-up the mean functional class was 1.8+/-0.6 in long-term survivors (preoperative 2.9+/-0.9, P<0.001) with no difference between the groups.

CONCLUSIONS

The technique of repair of postinfarction dyskinetic LVA should be adapted in each patient to the cavity size and extent of the scarring process into the septum and subvalvular mitral apparatus. Applying these considerations to the choice of the technique of repair, both techniques achieved satisfactory results with respect to perioperative mortality, late functional status and survival.

Alterations in left ventricular torsion in tachycardia-induced dilated cardiomyopathy

OBJECTIVE

Left ventricular torsion reduces transmural systolic gradients of fiber strain, and torsional recoil in early diastole is thought to enhance left ventricular filling. Left ventricular remodeling in dilated cardiomyopathy may result in changes in torsion dynamics, but these effects are not yet characterized. Tachycardia-induced cardiomyopathy is accompanied by systolic and diastolic heart failure and left ventricular remodeling. We hypothesized that cardiomyopathy would alter systolic and diastolic left ventricular torsion mechanics, and this hypothesis was tested by studying sheep before and after the development of tachycardia-induced cardiomyopathy.

METHODS

Implanted miniature radiopaque markers were used in 8 sheep to measure left ventricular geometry and function, maximal torsional deformation, and early diastolic recoil before and after rapid ventricular pacing was used to create tachycardia-induced cardiomyopathy.

RESULTS

All animals had significant heart failure with ventricular dilatation and remodeling. With tachycardia-induced cardiomyopathy, maximum torsion relative to control conditions decreased (1.69 degrees +/- 0.61 degrees vs 4.25 degrees +/- 2.33 degrees ), and early diastolic recoil was completely abolished (0.53 degrees +/- 1.19 degrees vs -1.17 degrees +/- 0.94 degrees ).

CONCLUSIONS

Cardiomyopathy is accompanied by decreased and delayed systolic left ventricular torsional deformation and loss of early diastolic recoil, which may contribute to left ventricular dysfunction by increasing systolic transmural strain gradients and impairing diastolic filling. Analysis of left ventricular torsion with radiofrequency-tagging magnetic resonance imaging should be explored to elucidate the role of torsion in patients with cardiomyopathy.