Long-term survival and functional results after aortic valve replacement in asymptomatic patients with chronic severe aortic regurgitation and left ventricular dysfunction

Early Identification of Decompensated Aortic Regurgitation With Stress Echocardiography

•Chronic severe AR progresses slowly with a long asymptomatic compensated phase.•Stress echocardiography (SE) has the ability to uncover subclinical LV dysfunction.•SE can identify patients with severe AR who may benefit from earlier intervention.

l -Arginine Can Enhance the Beneficial Effect of Losartan in Patients with Chronic Aortic Regurgitation and Isolated Systolic Hypertension

Information about the effects of angiotensin II receptor blocker (ARB) therapy on the hemodynamic and cardiac structure in patients with chronic aortic regurgitation (CAR) and isolated systolic hypertension (ISH) is limited. This study planned to test the hypothesis that l -arginine could further enhance the beneficial effect of an ARB, losartan, and provide a favorable effect on the natural history of CAR and ISH. Sixty patients with CAR and ISH were enrolled in a randomized, double-blind trial comparing hemodynamic and ultrasonic change in two treatment arms: losartan +  l -arginine and losartan-only treated groups. Serial echocardiographic and hemodynamic studies were evaluated before and after treatment. Both groups had a significant reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), left ventricular end-diastolic volume index (LVEDVI), LV end-systolic volume index (LVESVI), LV mass index (LVMI), and LV mean wall stress after 6- and 12-month treatment ( p <0.01 in all comparisons). Both groups had a significant increase in LV ejection fraction and exercise duration after 6- and 12-month treatment ( p  < 0.01 in all comparisons). Using multivariate linear regression analysis, only losartan +  l -arginine therapy achieved a significantly lower LVESVI (38.89 ± 0.23 mL/m ² ), LVEDVI (102.3 ± 0.3 mL/m ² ), LVMI (107.6 ± 0.3 g/m ² ), SBP (123.5 ± 1.0 mm Hg), and greater exercise duration (7.38 ± 0.02 minutes) than those of the losartan-only treated groups ( p <0.01 in all comparisons). These findings suggest that early co-administrative strategy provides a beneficial approach to favorably influence the natural history of CAR.

New classification of geometric patterns considering left ventricular volume in patients with chronic aortic valve regurgitation: Prevalence and association with adverse cardiovascular outcomes

BACKGROUND

Left ventricular (LV) remodeling due to aortic regurgitation (AR) often leads to maladaptive responses. We assessed the prevalence and clinical implications of LV remodeling considering LV volume, mass, and relative wall thickness at the time of AR diagnosis.

METHODS AND RESULTS

Between 2008 and 2017, 370 consecutive patients (mean age 67.3 ± 16.1 years, 56.5% males), with moderate or severe AR, were retrospectively analyzed. LV geometric patterns and clinical outcomes (cardiovascular death, hospitalization for heart failure, or aortic valve replacement) were evaluated. LV dilatation (LV end-diastolic volume >75 mL/m² ) was present in 228 patients (61.6%). Applying the new LV remodeling classification system, 40 (10.8%) patients had normal geometry, 14 (3.8%) concentric remodeling, 43 (11.6%) concentric hypertrophy (LVH), 45 (12.2%) indeterminate LVH, 38 (10.3%) mixed LVH, 93 (25.1%) dilated LVH, 54 (14.6%) eccentric LVH, and 43 (11.6%) eccentric remodeling. During a median follow-up of 3.48 years (25th-75th percentile 0.91-5.57), 97 (26.2%) had the combined endpoint. LV dilation (P < 0.001), LVH (P < 0.001), and LV remodeling patterns were significantly associated with the combined endpoint. After multivariable adjustment for age, EF, aortic stenosis, CAD history, and moderate mitral regurgitation, dilated LVH (HR 7.61, IC 95% 1.82-31.80; P = 0.005) and eccentric LVH (HR 7.91, IC 95% 1.82-34.38; P = 0.006) were associated with adverse outcome compared to eccentric remodeling, that showed the best event-free survival rate.

CONCLUSIONS

In a contemporary cohort of patients with AR, applying the new LV remodeling classification system, only a minority had normal geometry. Dilated LVH and eccentric LVH showed distinct outcome penalty after adjustment for confounders.

Survival after Aortic Valve Replacement for Aortic Regurgitation: Prediction from Preoperative Contractility Measurement

BACKGROUND

Noninvasive measurement of myocardial contractility (end-systolic wall stress-adjusted change in left ventricular ejection fraction from rest to exercise [ΔLVEF - ΔESS]) predicts heart failure, subnormal LVEFrest, and sudden death in asymptomatic patients with chronic severe aortic regurgitation (AR). Here we assess the relation of preoperative ΔLVEF - ΔESS to survival after aortic valve replacement (AVR).

METHODS

Patients who underwent AVR for chronic, isolated, pure severe AR (n = 66) were followed for 13.0 ± 6.4 event-free years. Preoperative ΔLVEF - ΔESS (from combined echocardiographic and radionuclide cineangiographic data) enabled cohort stratification into 3 terciles (-1 to -11% [normal or mild] contractility deficit, -12 to -16% [moderate], and ≤-17% [severe], identical with segregation in our earlier study) to relate preoperative contractility to postoperative survival and to age- and gender-matched US census data.

RESULTS

Since AVR, 22 patients died (average annual risk [AAR] for all-cause mortality for the entire co hort = 3.15%). Preoperative ΔLVEF - ΔESS predicted postoperative survival (p = 0.009, log rank test). By contractility terciles, all-cause AARs were 1.44, 2.58, and 6.40%. Survival was lower than among US census comparators (p < 0.02), but the "mild" tercile was indistinguishable from census data (p = ns). By multivariable Cox regression, survival prediction by pre-AVR ΔLVEF - ΔESS was independent of, and superior to, prediction by age at surgery, gender, preoperative functional class, LVEFrest, LVEFexercise, change in LVEFrest to exercise, and LV diastolic or systolic dimensions (p ≤ 0.01, pre-AVR ΔLVEF - ΔESS vs. other covariates).

CONCLUSION

In severe AR, preoperative contractility predicts post-AVR survival and may be prognostically superior to clinical, geometric and performance descriptors, potentially impacting on patient selection for surgery.

Current Management of Patients with Severe Aortic Regurgitation

OPINION STATEMENT

Chronic aortic regurgitation can result from various congenital and acquired anomalies and can be associated with proximal aortic disease. As the number of aortic valve procedures is growing, the incidence of post-procedural regurgitation also increases with associated morbidity. Typical evolution is characterized by a clinically silent phase of variable duration followed by a rather rapid decline with high incidence of adverse events. A challenge remains to find the optimal timing for an intervention: Patients are exposed to unnecessary surgical risks if treated prematurely, but peri- and post-operative prognosis is worse when the intervention is performed too late. Clinical evaluation and serial imaging tests can optimize the timing for intervention. Clinical follow-up should try to elucidate associated symptoms, with quantitative measurement of functional capacity as needed. Serial imaging examinations are required to identify sub-clinical left ventricular dysfunction or severe dilatation that should prompt a surgery. At least in selected cases, newer imaging modalities (MRI, 3D echocardiography) and/or biomarkers can help for the management of these patients, and more research is needed to determine if their systematic use can be beneficial. Medical treatment with vasodilators and anti-remodeling drugs can be helpful in some patients but should not replace or delay aortic valve surgery when indicated. Most patients will eventually be treated with surgical aortic valve replacement. Although possible in selected cases, transcatheter aortic valve replacement is not commonly used for patients with pure aortic regurgitation. For patients with prior aortic valve replacement and aortic regurgitation (paravalvular or intravalvular), emerging percutaneous approaches can be considered when available, especially for those at high surgical risk.

Aortic valve replacement for severe aortic regurgitation in asymptomatic patients with normal ejection fraction and severe left ventricular dilatation

OBJECTIVES

According to current guidelines, aortic valve surgery is a Class II indication for asymptomatic patients with severe aortic regurgitation (AR) accompanied by left ventricular (LV) ejection fraction (LVEF) ≥ 50% and left ventricular end-diastolic dimension (LVEDD) >70 mm. This study aims to assess the postoperative outcomes of asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD >70 mm after aortic valve replacement (AVR) and to identify prognostic indicators of the surgery, especially in terms of LV ejection fraction and degree of LV dilatation.

METHODS

We retrospectively identified 192 consecutive asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm who underwent isolated AVR from January 2003 to December 2013. Postoperative outcomes and prognostic indicators were evaluated and analysed.

RESULTS

Patients had a mean age of 52.4 ± 16.1 years, and 69.3% were male. The mean LVEF and the mean LVEDD were 58.6 ± 6.6% and 76.0 ± 6.9 mm, respectively. The in-hospital mortality rate was 2.1% and survival rates at 5 and 10 years were 94.5 and 86.6%, respectively. Multivariable analysis indicated that postoperative mortality was associated with age [hazard ratio (HR) 1.059, 95% confidence interval (CI): 1.010-1.125, P = 0.049], preoperative LVEF (HR 0.860 95% CI: 0.748-0.989, P = 0.035) and LVEDD (HR 1.094 95% CI: 1.008-1.188, P = 0.032). Receiver-operating characteristic analysis showed that preoperative LVEF < 55% and LVEDD ≥ 81 mm were the best cut-off values for predicting postoperative mortality. By subgroup analysis, patients with 50 ≤ LVEF < 55% had poorer 5- and 10-year survival rates of 87.4 and 74.8% compared with 97.3% and 91.7% for patients with LVEF ≥ 55% (P = 0.023). Patients with LVEDD ≥ 81 mm had poorer 5- and 10-year survival rates of 85.6 and 72.6% compared with 98.2% and 85.6% for those with LVEDD < 81 mm (P = 0.027).

CONCLUSIONS

AVR can be performed with satisfactory outcomes for severe aortic regurgitation in asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm. It is observed that 50% ≤ LVEF < 55% or LVEDD ≥ 81 mm are associated with poorer prognosis in patients undergoing AVR.

Drug Therapy for Heart Valve Diseases

Valvular heart diseases (VHDs) are progressive. When not caused by acute comorbidities they are generally characterized by long asymptomatic phases during which hemodynamic severity may progress leading to morbidity and mortality. Treatment depends on VHD type and severity but when severe and symptomatic, usually involves mechanical intervention. Asymptomatic patients, and those who lack objective descriptors associated with high risk, are closely observed clinically with optimization of associated cardiovascular risk factors until surgical indications develop. Though often prescribed based on theory, no rigorous evidence supports pharmacological therapy in most chronic situations though drugs may be appropriate in acute valvular diseases, or as a bridge to surgery in severely decompensated patients. Herein, we examine evidence supporting drug use for chronic VHDs.

PINOT NOIR: pulmonic insufficiency improvement with nitric oxide inhalational response

BACKGROUND

Tetralogy of Fallot (TOF) repair and pulmonary valvotomy for pulmonary stenosis (PS) lead to progressive pulmonary insufficiency (PI), right ventricular enlargement and dysfunction. This study assessed whether pulmonary regurgitant fraction measured by cardiovascular magnetic resonance (CMR) could be reduced with inhaled nitric oxide (iNO).

METHODS

Patients with at least moderate PI by echocardiography undergoing clinically indicated CMR were prospectively enrolled. Patients with residual hemodynamic lesions were excluded. Ventricular volume and blood flow sequences were obtained at baseline and during administration of 40 ppm iNO.

RESULTS

Sixteen patients (11 with repaired TOF and 5 with repaired PS) completed the protocol with adequate data for analysis. The median age [range] was 35 [19-46] years, BMI was 26 ± 5 kg/m(2) (mean ± SD), 50% were women and 75% were in NYHA class I. Right ventricular end diastolic volume index for the cohort was 157 ± 33 mL/m(2), end systolic volume index was 93 ± 20 mL/m(2) and right ventricular ejection fraction was 40 ± 6%. Baseline pulmonary regurgitant volume was 45 ± 25 mL/beat and regurgitant fraction was 35 ± 16%. During administration of iNO, regurgitant volume was reduced by an average of 6 ± 9% (p=0.01) and regurgitant fraction was reduced by an average of 5 ± 8% (p=0.02). No significant changes were observed in ventricular indices for either the left or right ventricle.

CONCLUSION

iNO was successfully administered during CMR acquisition and appears to reduce regurgitant fraction in patients with at least moderate PI suggesting a potential role for selective pulmonary vasodilator therapy in these patients.

TRIALS REGISTRATION

ClinicalTrials.gov, NCT00543933.

Angiotensin II-converting enzyme inhibition improves survival, ventricular remodeling, and myocardial energetics in experimental aortic regurgitation

BACKGROUND

Aortic valve regurgitation (AR) is a volume-overload disease causing severe eccentric left ventricular (LV) hypertrophy and eventually heart failure. There is currently no approved drug to treat patients with AR. Many vasodilators including angiotensin-converting enzyme inhibitors have been evaluated in clinical trials, but although some results were promising, others were inconclusive. Overall, no drug has yet been able to improve clinical outcome in AR and the controversy remains. We have previously shown in an animal model that captopril (Cpt) reduced LV hypertrophy and protected LV systolic function, but we had not evaluated the clinical outcome. This protocol was designed to evaluate the effects of a long-term Cpt treatment on survival in the same animal model of severe aortic valve regurgitation.

METHODS AND RESULTS

Forty Wistar rats with AR were treated or untreated with Cpt (1 g/L in drinking water) for a period of 7 months to evaluate survival, myocardial remodeling, and function by echocardiography as well as myocardial metabolism by µ positron emission tomography scan. Survival was significantly improved in Cpt-treated animals with a survival benefit visible as soon as after 4 months of treatment. Cpt reduced LV dilatation and LV hypertrophy. It also significantly improved the myocardial metabolic profile by restoring the level of fatty acids metabolic enzymes and use.

CONCLUSIONS

In a controlled animal model of pure severe aortic valve regurgitation, Cpt treatment reduced LV remodeling and LV hypertrophy and improved myocardial metabolic profile and survival. These results support the need to reevaluate the role of angiotensin-converting enzyme inhibitors in humans with AR in a large, carefully designed prospective clinical trial.

Prospective validation of the prognostic usefulness of B-type natriuretic peptide in asymptomatic patients with chronic severe aortic regurgitation

OBJECTIVES

The purpose of this study was to determine the independent and additive prognostic value of B-type natriuretic peptide (BNP) in patients with severe asymptomatic aortic regurgitation and normal left ventricular function.

BACKGROUND

Early surgery could be advisable in selected patients with chronic severe aortic regurgitation, but there are no uniform criteria to identify candidates who could benefit from this strategy. Assessment of BNP has not been studied for this purpose.

METHODS

We prospectively evaluated 294 consecutive patients with severe asymptomatic organic aortic regurgitation and left ventricular ejection fraction above 55%. The first 160 consecutive patients served as the derivation cohort and the next 134 patients served as a validation cohort. The combined endpoint was the occurrence of symptoms of congestive heart failure, left ventricular dysfunction, or death at follow-up.

RESULTS

The endpoint was reached in 45 patients (28%) of the derivation set and in 35 patients (26%) of the validation cohort. Receiver-operator characteristic curve analysis yielded an optimal cutoff point of 130 pg/ml for BNP that was able to discriminate between patients at higher risk in both cohorts. BNP was the strongest independent predictor by multivariate analysis in the derivation set (odds ratio: 6.9 [95% confidence interval: 2.52 to 17.57], p < 0.0001) and the validation set (odds ratio: 6.7 [95% confidence interval: 2.9 to 16.9], p = 0.0001).

CONCLUSIONS

Among patients with severe asymptomatic aortic regurgitation and normal left ventricular function, BNP ≥130 pg/ml categorizes a subgroup of patients at higher risk. Because of its incremental prognostic value, we believe BNP assessment should be used in the routine clinical evaluation of these patients.

[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.

Medical treatment of asymptomatic chronic aortic regurgitation

Chronic aortic regurgitation results in left ventricular (LV) dilation, increased LV work and, eventually, a decline in LV function and heart failure. An important question is whether pharmacological therapy could preserve LV function and delay the need for aortic valve replacement. Vasodilators have a number of theoretical advantages. By lowering blood pressure, they reduce the regurgitant volume and decrease LV afterload. This article summarizes the clinical studies that have evaluated vasodilators in asymptomatic patients with chronic aortic regurgitation. Some studies suggest favorable effects on LV function and clinical outcomes, but results are inconsistent, making it difficult to draw definite conclusions. In general, studies have been too small to reliably evaluate the overall benefits and risks of this treatment, and in several studies there was no significant difference in measured blood pressure by treatment allocation. For these reasons, decisions on whether vasodilators are indicated in individual patients must currently be based on clinical judgment alone.

Left ventricular mechanics in asymptomatic normotensive and hypertensive patients with aortic regurgitation

BACKGROUND

The aims of this study were to detect subclinical left ventricular (LV) dysfunction and to determine the impact of arterial hypertension on LV systolic function using speckle-tracking echocardiography in patients with chronic aortic regurgitation (AR).

METHODS

Sixty-eight patients with AR and 47 healthy controls were included in the study. LV rotation and longitudinal, radial, and circumferential strain were measured using speckle-tracking imaging.

RESULTS

Longitudinal axis dysfunction was found in patients with moderate AR with hypertension but was not present in patients with moderate AR without hypertension. Radial strain in patients with moderate AR was unchanged, but reduced levels were noted at the apical level in patients with severe AR without hypertension and preserved in those with severe hypertensive AR. LV basal rotation was reduced in patients with severe AR, whereas apical rotation was increased in those with moderate AR. LV torsion was reduced in patients with severe AR.

CONCLUSIONS

Patients with asymptomatic AR show subclinical LV longitudinal axis dysfunction, with more attenuation demonstrated in hypertensive than in normotensive patients.

Persistent Diastolic Dysfunction Late After Valve Replacement in Severe Aortic Regurgitation

Background— Regression of left ventricular (LV) hypertrophy with normalization of diastolic function has been reported in patients with aortic stenosis late after aortic valve replacement (AVR). The purpose of the present study was to evaluate the effect of AVR on LV function and structure in chronic aortic regurgitation early and late after AVR.

Methods and Results— Twenty-six patients were included in the present analysis. Eleven patients with severe aortic regurgitation were studied before, early (21 months) and late (89 months) after AVR through the use of LV biplane angiograms, high-fidelity pressure measurements, and LV endomyocardial biopsies. Fifteen healthy subjects were used as controls. LV systolic function was determined from biplane ejection fraction and midwall fractional shortening. LV diastolic function was calculated from the time constant of LV relaxation, peak filling rates, and myocardial stiffness constant. LV structure was assessed from muscle fiber diameter, interstitial fibrosis, and fibrous content. LV muscle mass decreased significantly by 38% early and 55% late after surgery. Ejection fraction was significantly reduced preoperatively and did not change after AVR ( P =NS). LV relaxation was significantly prolonged before surgery (89±28 ms) but was normalized late after AVR (42±14 ms). Early and late peak filling rates were increased preoperatively but normalized postoperatively. Diastolic stiffness constant was increased before surgery (22±6 versus 9±3 in control subjects; P =0.0003) and remained elevated early and late after AVR (23±4; P =0.002). Muscle fiber diameter decreased significantly after AVR but remained increased at late follow-up. Interstitial fibrosis was increased preoperatively and increased even further early but decreased late after AVR. Fibrosis was positively linearly correlated to myocardial stiffness and inversely correlated to LV ejection fraction.

Conclusions— Patients with aortic regurgitation show normalization of macroscopic LV hypertrophy late after AVR, although fiber hypertrophy persists. These changes in LV myocardial structure late after AVR are accompanied by a change in passive elastic properties with persistent diastolic dysfunction.

Clinical Trial Registration— URL: http://www.clinicaltrial.gov. Unique identifier: NCT00976625.

Valve Pathology in Heart Failure: Which Valves Can Be Fixed?

Heart transplantation has evolved to become the gold standard treatment for patients who have symptoms of severe congestive heart failure associated with end-stage heart disease. From an epidemiologic perspective, this treatment is "trivial" because less than 2800 patients in the United States are offered transplantation because of limitations of age, comorbid conditions, and donor availability. New surgical strategies to manage patients who have severe end-stage heart disease have therefore evolved to cope with the donor shortage in heart transplantation and have included high-risk coronary artery revascularization, cardiomyoplasty, and high-risk valvular repair or replacement.

Assessment of Myocardial Velocities and Global Function of the Left Ventricle in Asymptomatic Patients with Moderate-to-Severe Chronic Aortic Regurgitation: A Tissue Doppler Echocardiographic Study

OBJECTIVE

Asymptomatic patients with chronic aortic regurgitation (AR) have an excellent prognosis in the presence of preserved systolic function. It is a challenge to recognize patients with subclinical myocardial dysfunction in AR. Conventional parameters still have many drawbacks in predicting early left ventricular (LV) dysfunction. Pulsed-wave tissue Doppler imaging (PW-TDI) is a useful noninvasive technique for evaluating global and regional LV systolic function. In this study, we aimed to assess clinical usefulness of TDI in predicting early disturbance of myocardial contractility in asymptomatic patients with significant AR and preserved left ventricular systolic function.

METHODS AND THE RESULTS

Echocardiograms were obtained in 32 AR patients and 33 healthy subjects. In addition to conventional parameters, regional myocardial velocities, isovolumetric contraction time (mICT), isovolumetric relaxation time (mIRT), and ejection time (mET) of left ventricle were obtained by TDI and modified LV myocardial performance index (MPI) was calculated. In AR, peak systolic velocity (Sm) of septal and anterior mitral annulus, and mean Sm was significantly lower, and LVMPI was significantly higher compared to control group.

CONCLUSION

The data obtained by TDI show that LV MPI is lengthened, and systolic myocardial velocities are shortened in patients having chronic AR with normal LV systolic function according to conventional echocardiographic parameters. This suggests that LV long-axis contraction and global LV performance are preciously and noticeably decreased in patients with moderate-to-severe chronic AR despite normal LV ejection fraction.

Vasodilator therapy in patients with aortic insufficiency: a systematic review

BACKGROUND

The use of vasodilators to improve long-term outcomes in asymptomatic patients with chronic aortic insufficiency (AI) is controversial.

METHODS

We reviewed MEDLINE, PREMEDLINE, Current Contents, and Cochrane databases to identify relevant clinical trials on asymptomatic patients with chronic AI of at least moderate severity. We included those studies that involved long-term vasodilator therapy (including hydralazine, calcium-channel blockers, and angiotensin-converting enzyme inhibitors) and assessed either hemodynamic and structural parameters or clinical outcomes. Data on patient demographics, study protocols, and outcomes were abstracted.

RESULTS

Ten studies with 544 asymptomatic patients with chronic AI were identified. Treatment duration with vasodilators ranged from 12 weeks to 7 years. Of these, 8 studies compared vasodilators with placebo or no therapy, with 5 demonstrating improvements in at least 1 hemodynamic or structural parameter with vasodilators and 3 showing little or no apparent benefit. The remaining 2 studies directly compared outcomes between 2 different vasodilators. Both of these studies demonstrated greater improvements in hemodynamic and structural parameters with angiotensin-converting enzyme inhibitors compared with hydralazine and nifedipine. Clinical outcomes were primarily reported in only 2 of the 10 studies. Although one study suggested that the use of vasodilators slowed the rate of progression to surgery for aortic valve replacement, another showed no difference.

CONCLUSIONS

Vasodilators inconsistently improve hemodynamic and structural parameters in asymptomatic patients with chronic AI. In addition, the impact of vasodilators on clinical outcomes is largely uncertain and requires further study.

Are vasodilators still indicated in the treatment of severe aortic regurgitation?

Aortic regurgitation (AR) is a valve disease that causes severe complications and reduces life expectancy. Surgical correction is required in the late stages of the disease. In less advanced forms, treatment with vasodilators is a consideration. The available evidence suggests that this type of treatment has a favorable effect on the consequences of AR, particularly left ventricular remodeling. However, the impact of vasodilators on clinical endpoints complicating the course of AR remains in doubt. The limited evidence supporting or opposing the utilization of vasodilators in AR hinders drawing firm conclusions and emphasizes the process of individualized interpretation of the clinical presentation of patients with the disease.

Role of vasodilators in regurgitant valve disease

Vasodilator therapy is designed to reduce regurgitant volume and improve left ventricular function. Acute administration reduces vascular resistance and decreases regurgitant volume and left ventricular filling pressure. These effects may be clinically useful in acute regurgitations, but less consistent results have been reported in long-term therapy. In chronic mitral functional regurgitation, vasodilator therapy has proved to have clinical or prognostic benefit only when heart failure or poor ventricular function is present. The indication of vasodilator treatment in aortic regurgitation has raised significant controversy. Several studies with small series have shown beneficial effects on regurgitant volume, ejection fraction, and mass of the left ventricle. Nevertheless, in the only two randomized long-term follow-up studies, results differed completely. In our experience, both nifedipine and enalapril failed to reduce the need for valvular surgery or show benefits in echocardiographic parameters. Vasodilator therapy would be indicated only in patients with severe aortic regurgitation and systemic hypertension, or when surgery is contraindicated.

Long-term vasodilator therapy in patients with severe aortic regurgitation

BACKGROUND

Vasodilator therapy can reduce the left ventricular volume and mass and improve left ventricular performance in patients with aortic regurgitation. Accordingly, it has been suggested that such therapy may reduce or delay the need for aortic-valve replacement.

METHODS

We randomly assigned 95 patients with asymptomatic severe aortic regurgitation and normal left ventricular function to receive open-label nifedipine (20 mg every 12 hours), open-label enalapril (20 mg per day), or no treatment (control group) to identify the possible beneficial effects of vasodilator therapy on left ventricular function and the need for aortic-valve replacement.

RESULTS

After a mean of seven years of follow-up, the rate of aortic-valve replacement was similar among the groups: 39 percent in the control group, 50 percent in the enalapril group, and 41 percent in the nifedipine group (P=0.62). In addition, there were no significant differences among the groups in aortic regurgitant volume, left ventricular size, left ventricular mass, mean wall stress, or ejection fraction. One year after valve replacement, the left ventricular end-diastolic diameter and end-systolic diameter had decreased to a similar degree among the patients who underwent surgery in each of the three groups, and all the patients had a normal ejection fraction.

CONCLUSIONS

Long-term vasodilator therapy with nifedipine or enalapril did not reduce or delay the need for aortic-valve replacement in patients with asymptomatic severe aortic regurgitation and normal left ventricular systolic function. Furthermore, such therapy did not reduce the aortic regurgitant volume, decrease the size of the left ventricle, or improve left ventricular function.