Valve Replacement for Regurgitant Lesions of the Aortic or Mitral Valve in Advanced Left Ventricular Dysfunction

Outcomes of Aortic Valve Replacement for Chronic Aortic Insufficiency: Analysis of the Society of Thoracic Surgeons Database

BACKGROUND

This study evaluated outcomes and risk factors for surgical aortic valve replacement (SAVR) for aortic insufficiency (AI) in a national cohort. We analyzed the incidence, outcomes, and risk factors for SAVR for AI in the Society of Thoracic Surgeons Adult Cardiac Surgery Database.

METHODS

The national database was queried for patients with moderate or greater AI undergoing isolated SAVR between July 2011 and December 2018. Patients with moderate or greater aortic stenosis, acute dissection, active endocarditis, concomitant procedures, or emergent operation were excluded. AI was staged using guideline criteria based on symptoms and ventricular remodeling. Operative mortality and morbidity were compared between stages, and risk factors for operative death were identified.

RESULTS

A total of 12,564 patients underwent isolated SAVR for AI from 2011 to 2018. Patients were most frequently AI stage D (7019 [57.5%]), compared with B (1405 [11.2%]), C1 (1128 [9.0%]), or C2 (1325 [10.5%]). Operative mortality was 1.1% overall, and increased between stage C1, C2, and D (0.4% vs 0.7% vs 1.6%, respectively, P < .01), along with major morbidity (5.1% vs 7.5% vs 9.9%, respectively; P < .01). Mortality was higher in patients with severe ventricular dilation and an ejection fraction of less than 0.30 (2.7% vs 1.0%, P < .01). Risk factors for death were symptomatic AI, decreased ejection fraction, age, weight, body surface area, and dialysis.

CONCLUSIONS

Operative mortality and morbidity for isolated SAVR for AI is very low in a national cohort, providing a benchmark for future transcatheter approaches. Operative risk increases with advanced ventricular remodeling. SAVR before development of ventricular remodeling may be appropriate in patients with severe AI.

Optimal Management of Chronic Severe Aortic Regurgitation - How to Determine Cutoff Values for Surgical Intervention?

Aortic regurgitation (AR) is a common valvular heart disease, but the optimal timing of surgical intervention remains controversial. In the natural history of chronic severe AR, sudden death is rare, and the annual mortality rate is comparatively low. Considering the hemodynamic features of combined volume and pressure overload and long-term compensation in patients with chronic AR, symptoms related to AR do not frequently occur. Therefore, the progression of left ventricular (LV) dysfunction is a key factor in determining the timing of surgical intervention in patients with severe chronic AR. In addition to symptoms, an ejection fraction <50% and an LV endsystolic diameter (LVESD) >45 mm are appropriate cutoff values for surgical intervention in Japanese patients, whereas LV end-diastolic diameter is not a good indicator. An LVESD index of 25 mm/m²is controversial, because adjusting for body size may cause overcorrection in Japanese patients who have a small body size compared with Westerners. Accumulation of data from the Japanese population is indispensable for establishing guidelines on optimal management of patients with chronic AR.

Predictors of Long-Term Outcome of Isolated Surgical Aortic Valve Replacement in Aortic Regurgitation With Reduced Left Ventricular Ejection Fraction and Extreme Left Ventricular Dilatation

The management of severe aortic regurgitation (AR) in patients with reduced left ventricular function and extreme left ventricular dilatation presents a therapeutic dilemma. This study aims to assess risk factors of aortic valve replacement (AVR) for these particular population based on its performances. Two hundred twelve severe AR patients accompanied by left ventricular ejection fraction (LVEF) <50% and left ventricular end-diastolic dimension (LVEDD) ≥70 mm who underwent isolated AVR between January 2007 and December 2016 were identified retrospectively. Logistic regression and receiver operating characteristic were used to analyze prognostic indicators for in-hospital mortality while Kaplan-Meier analysis for long-term survival. Mean age was 56 ± 13 years with mean LVEF 40 ± 7% and LVEDD 78 ± 6 mm. In-hospital mortality rate was 7%, and survival rates at 5 and 10 years were 88 ± 4% and 73 ± 10%, respectively. Logistic regression analysis indicated in-hospital mortality was associated with preoperative age and LVEF. Receiver operating characteristic analysis showed LVEF = 35% was the best cut-off value at which to predict in-hospital death. Kaplan-Meier analysis revealed patients with markedly reduced LV function (LVEF <35%) had lower survival rates compared with other patients with moderate LV dysfunction (LVEF 36% to 50%) (1-, 5-, and 10-year: 90 ± 4%, 64 ± 7%, and 55 ± 14%, vs 97 ± 1%, 94 ± 3%, and 76 ± 7%, p <0.001). An age-matched analysis showed similar trend (p = 0.020). In Conclusion, AVR may be unsafe for severe AR patients with markedly reduced LV function (LVEF <35%) and extreme left ventricular dilatation (LVEDD >70 mm) due to poor postoperative early- and long-term outcomes.

[Surgery of aortic regurgitation with reduced left ventricular function]

BACKGROUND

Aortic valve replacement improves clinical symptoms and left ventricular systolic function in patients with chronic aortic regurgitation despite a higher surgical risk. The objective of this study is to determine if left ventricular function will be normalized after surgery.

PATIENTS AND METHOD

This retrospective study included 40 patients (nine females and 31 males) with chronic aortic regurgitation and left ventricular systolic dysfunction who were evaluated by echocardiography Doppler. Were included patients with left ventricular ejection fraction less or equal to 45%. Ages ranged from 18 to 77 years (mean = 46.4 ± 12.6 years). Preoperatively, six patients (15%) were asymptomatic, ten (25%) were in NYHA II, half (50%) in NYHA III and four (10%) in NYHA IV. The mean preoperative ejection fraction (EF) was 36.2 ± 2%. The mean end systolic and diastolic dimensions were 61.7 ± 8.5 mm and 78.9 ± 9.7 mm respectively. Aortic regurgitation was quantified grade III in sixteen patients (40%) and grade IV in twenty-four (60%).

RESULTS

Thirty-seven patients underwent aortic valve replacement and three Bentall operations. Hospital mortality was 7.5% (3/40). The mean follow-up period was 69.7 months. All survivor patients were investigated. Out of these, five were lost and 32 were controlled. Symptomatic improvement was noted in most of the survivors. Sixty percent (24/40) were severely symptomatic before and only 6.25% (2/32) during follow-up. The ejection fraction increased significantly after surgery (36.2 ± 2% in preoperative period vs. 55.2 ± 10% in postoperative period, P < 0.02). Left ventricular diameters decreased significantly also. Survival rates were 3-year 94%, 5-year 91% and 7-year 89%.

CONCLUSION

Despite reduced left ventricular systolic function, aortic valve replacement in chronic aortic regurgitation was associated with acceptable operative risk. Surgery improves functional status, symptoms and ejection fraction in most patients.

Survival in patients with severe aortic regurgitation and severe left ventricular dysfunction is improved by aortic valve replacement: results from a cohort of 166 patients with an ejection fraction < or =35%

BACKGROUND

Aortic valve replacement (AVR) in patients with severe aortic regurgitation (AR) and left ventricular (LV) dysfunction entails a higher surgical risk. Though it may improve symptoms and LV size, it is not known whether it translates into a survival benefit.

METHODS AND RESULTS

This retrospective cohort study included patients screened from our echocardiographic database between 1993 and 2007 for patients with severe AR and LV ejection fraction (EF) < or =35%. Charts reviews were conducted for clinical, pharmacological, and surgical information. Mortality data were obtained from the social security death index and analyzed as a function of AVR adjusted for the propensity score. Of the 785 patients with severe AR, 166 patients had severe LV dysfunction defined as an EF < or =35%: 69% of these were men, age 65+/-16 years, and LV EF was 23+/-8%. Kaplan-Meier analysis revealed that performance of AVR (n=53) was associated with a better survival (P=0.001). Adjusted for the propensity score, AVR was associated with a significantly lower mortality hazard (HR 0.59, CI 0.42 to 0.98, P=0.04).

CONCLUSIONS

There is a clear reluctance to offer AVR in a large number of patients with severe AR associated with LV dysfunction. However, the performance of AVR in these patients is associated with a mortality benefit supporting the current ACC/AHA guidelines.

Improved Outcomes After Aortic Valve Surgery for Chronic Aortic Regurgitation With Severe Left Ventricular Dysfunction

OBJECTIVES

Among patients undergoing aortic valve surgery for chronic aortic regurgitation (AR), we sought to: 1) compare survival among those with and without severe left ventricular dysfunction (LVD); 2) identify risk factors for death, including LVD and date of operation; and 3) estimate contemporary risk for cardiomyopathic patients.

BACKGROUND

Patients with chronic AR and severe LVD have been considered high risk for aortic valve surgery, with limited prognosis. Transplantation is considered for some.

METHODS

From 1972 to 1999, 724 patients underwent surgery for chronic AR; 88 (12%) had severe LVD. They were propensity matched to patients with nonsevere LVD to compare hospital mortality, interaction of operative date with severity of LVD, and late survival. Propensity score-adjusted multivariable analysis was performed for all 724 patients to identify risk factors for death.

RESULTS

Survival was lower (p = 0.04) among patients with severe LVD than among matched patients with nonsevere LVD (30-day, 1-, 5-, and 25-year survival estimates were 91% vs. 96%, 81% vs. 92%, 68% vs. 81%, and 5% vs. 12%, respectively). However, survival of patients with severe LVD improved dramatically across the study time frame (p = 0.0004): hospital mortality decreased from 50% in 1975 to 0% after 1985, and time-related survival in patients with severe LVD operated on since 1985 became equivalent to that of matched patients with nonsevere LVD (p = 0.96).

CONCLUSIONS

Neutralizing risk of severe LVD has improved early and late survival such that aortic valve surgery for chronic AR and cardiomyopathy is no longer a high-risk procedure for which transplantation is the best option.

Medical and surgical treatment of chronic mitral regurgitation

Chronic severe mitral regurgitation is a progressive disease that can lead to left ventricular dysfunction. New information on the natural history of the disease, along with advances in surgical techniques, has changed the roles of medical and surgical therapies. There is no well-defined role for medical therapy in chronic mitral regurgitation. The goal of the treating physician is therefore to identify the optimal timing for surgical intervention. The timing of surgical intervention depends primarily on two factors: (i) clinical symptoms and (ii) the left ventricular response to volume overload. However, the aetiology of mitral regurgitation, the likelihood of surgical repair, the occurrence of atrial fibrillation and the presence of pulmonary hypertension, together with the haemodynamic response to exercise, are important factors in the optimal surgical timing. New concepts in the understanding of the natural history of the disease coupled with success of mitral repair have recently resulted in a widespread evolution towards earlier surgery.

Nontransplant surgical options for congestive heart failure

Although advanced heart failure has been considered the main indication for heart transplantation, the increasing number of candidates and shortage of organs for transplantation, with accumulating waiting lists, has originated another look into more conventional surgery, previously considered of prohibitive risk. In fact, many cases are a result of anatomic lesions that can be corrected by conventional surgery, and in the past decade many surgical groups have obtained good and even excellent results in the treatment of aortic stenosis with low output, and in aortic and mitral regurgitation with severe left ventricular (LV) dysfunction. Also, ischemic and idiopathic dilated cardiomyopathy have been successfully treated by several types of LV remodeling surgery, with or without coronary grafting. Many of these procedures achieved excellent operative, medium-, and long-term results and survival, which match well those observed with cardiac transplantation, most often with advantages in the quality of life and, not unimportantly, in financial costs. For operated patients, especially those with ischemic cardiomyopathy, close follow-up for cardiac failure is extremely important in order to detect the right moment for heart transplantation, if it becomes necessary.

Ten-year clinical laboratory follow-up after application of a symptom-based therapeutic strategy to patients with severe chronic aortic regurgitation of predominant rheumatic etiology

OBJECTIVES

This study was designed to assess the feasibility and the long-term results of a symptom-based strategy of aortic valve replacement in a Brazilian population with predominant rheumatic etiology.

BACKGROUND

Optimal criteria for valve replacement in aortic regurgitation (AR) are still not entirely clear. The appearance of symptoms is an indication for surgery, but may be associated with myocardial damage. Although cardiac imaging data have provided a safer guide for such decisions, the use of symptom-based surgical indication has not been validated and might conceivably be better in populations with predominant rheumatic etiology and younger age.

METHODS

Echocardiography and rest-exercise radionuclide ventriculography were performed in 75 patients with severe AR, age 28 +/- 9 years, over a period of 10 +/- 0.69 years. Thirty-seven patients developed symptoms and underwent aortic valve replacement surgery within six months. Thirty-eight patients remained asymptomatic and were managed medically.

RESULTS

Survival was 100% in asymptomatic patients and 82% in symptomatic. Surgical treatment caused marked ventricular remodeling, with ventricular diameter involution and an improvement of rest-exercise ejection fraction percent variation. Multivariate analysis showed that the probability of developing symptoms within 10 years was 58% for a patient with a left ventricular end-diastolic diameter > or =70 mm and 76% for a patient with left ventricular end-systolic (LVESD) > or =50 mm. Logistic regression identified LVESD and age as the most predictive and specific, but not sensitive, indicators of symptom development.

CONCLUSIONS

Application of a standardized therapeutic strategy to patients with severe AR and predominant rheumatic etiology resulted in 90.6% survival after 10 years of follow-up.

Evolving strategies for surgical management of patients with severe left ventricular dysfunction

As a result of an increasing population with advanced congestive heart failure and the lack of growth in cardiac transplantation, surgical treatments for heart failure have been re-examined. These therapies represent the evolution of well-known operations such as coronary bypass surgery and valve surgeries, and the more novel left ventricular reconstruction and operations aimed at inhibiting left ventricular remodeling. When performed by surgeons with experience in this evolving speciality within cardiovascular surgery, surgery for advanced heart failure is a treatment of choice for many patients.

Novel suture device for beating-heart mitral leaflet approximation

BACKGROUND

This investigation evaluates the potential of using a novel suturing device to achieve mitral valve repair (Alfieri type) on a beating heart without cardiopulmonary bypass.

METHODS

Eight healthy adult sheep were anesthetized and the chest was opened via a left thoracotomy. The suture device was directly inserted into the appendage of the left atrium. Suction ports on the distal tip of the device grasped and approximated the mitral leaflets while the heart was beating. Two-dimensional echocardiography and intracardiac pressure monitoring at the tip of the device were utilized to guide the procedure. The device was used to place two single sutures across the two leaflets at the center of the mitral valve. A knot pusher with integrated cutter was used to tie the sutures and cut the suture ends.

RESULTS

In all animals, the free margins of the mitral leaflets were successfully grasped and approximated by this device. Echocardiography confirmed successful deployment of the sutures in all cases, with a figure-of-eight appearance of the valve and normal valve hemodynamic function after placement of the sutures. Mid-leaflet approximation was verified at autopsy immediately after the procedure. No tissue damage was observed.

CONCLUSIONS

This study demonstrates that mitral valve repair (Alfieri type) can be performed safely and consistently on a beating heart without cardiopulmonary bypass using this new tissue approximation suture device. This technique may be applicable to the treatment of ischemic mitral regurgitation in conjunction with revascularization procedures or to mitral regurgitation in heart failure patients.

Aortic valve surgery in patients with left ventricular dysfunction

Patient with advanced left ventricular dysfunction and heart failure symptoms, either secondary to severe aortic stenosis and a low transvalvular gradient, or chronic aortic insufficiency are sometimes referred for cardiac transplantation. Now, with improvements in both myocardial protection and better valve prostheses, aortic valve surgery for patients with even the most advanced ventricular dysfunction can be performed with low risk.

Surgical treatments for heart failure

The surgical options for CHF are a part of a larger paradigm shift in management. Viable and effective surgical options other than cardiac transplant and ventricular assist devices clearly exist and are applicable to a large portion of patients with CHF. These surgical therapies are of acceptable risk before decompensated CHF develops. The rapidly evolving therapies for altering LV remodeling, which underlies CHF progression, are an exciting area that may be joined in the future by molecular advances in myoblast transfer and gene therapy. These therapies are the basis of the discipline of CHF surgery within cardiovascular surgery.

Treatment of chronic mitral regurgitation

BACKGROUND

Chronic, severe mitral regurgitation is a common clinical entity that can lead to progressive, irreversible left ventricular dysfunction. New information on the natural history of this condition, coupled with advances in surgical technique, have changed the roles of medical and surgical therapies.

METHODS

The current medical and surgical literature regarding chronic mitral regurgitation is critically reviewed.

RESULTS

There is no well-defined role for medical therapy in chronic mitral regurgitation. The goal of the treating physician is therefore to choose the optimal timing for surgical intervention. This process begins with noninvasive quantification of the degree of regurgitation. If severe, a careful search for signs or symptoms of impending left ventricular dysfunction should follow. Recent advances in surgical techniques for mitral valve repair allow for correction of the valvular defect with minimal mortality risk and improved preservation of ventricular function and are an impetus for early operative intervention. Mitral valve repair may also be beneficial in the setting of severe dilated cardiomyopathy.

CONCLUSIONS

The development of techniques for mitral valve repair has altered the treatment paradigm for severe mitral regurgitation. Surgical intervention before the onset of left ventricular dysfunction is recommended.