Symptoms, left ventricular function, and timing of valve replacement surgery in patients with aortic regurgitation

Predicting the need of aortic valve surgery in patients with chronic aortic regurgitation: a comparison between cardiovascular magnetic resonance imaging and transthoracic echocardiography

To compare the ability of cardiac magnetic resonance tomography (CMR) and transthoracic echocardiography (TTE) to predict the need for valve surgery in patients with chronic aortic regurgitation on a mid-term basis. 66 individuals underwent assessment of aortic regurgitation (AR) both in CMR and TTE between August 2012 and April 2017. The follow-up rate was 76% with a median of 5.1 years. Cox proportional hazards method was used to assess the association of the time-to-aortic-valve-surgery, including valve replacement and reconstruction, and imaging parameters. A direct comparison of most predictive CMR and echocardiographic parameters was performed by using nested-factor-models. Sixteen patients (32%) were treated with aortic valve surgery during follow-up. Aortic valve insufficiency parameters, both of echocardiography and CMR, showed good discriminative and predictive power regarding the need of valve surgery. Within all examined parameters AR gradation derived by CMR correlated best with outcome [χ² = 27.1; HR 12.2 (95% CI: 4.56, 36.8); (p < 0.0001)]. In direct comparison of both modalities, CMR assessment provided additive prognostic power beyond echocardiographic assessment of AR but not vice versa (improvement of χ² from 21.4 to 28.4; p = 0.008). Nested model analysis demonstrated an overall better correlation with outcome by using both modalities compared with using echo alone with the best improvement in the moderate to severe AR range with an echo grade II out of III and a regurgitation fraction of 32% in CMR. This study corroborates the capability of CMR in direct quantification of AR and its role for guiding further treatment decisions particularly in patients with moderate AR in echocardiography.

[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.

Effect of preoperative ejection fraction, left ventricular systolic dimension and hemoglobin level on survival after aortic valve surgery in patients with severe chronic aortic regurgitation

Surgical indications in patients with severe chronic aortic regurgitation (AR) and normal left ventricular (LV) ejection fractions (EF) remain to be established. The aim of this study was to identify prognostic indicators after surgery in patients with severe AR and normal LV systolic function. Preoperative clinical and echocardiographic characteristics were evaluated in 284 consecutive patients with chronic severe AR who underwent aortic valve surgery. Of these patients, 169 had normal (≥50%) and 115 had depressed (<50%) preoperative LV EFs. All-cause mortality was observed for a median of 39.9 months. Of 284 patients, 7 (4.4%) with normal LV EFs and 15 (12.0%) with depressed LV EFs died during follow-up after aortic valve surgery (p = 0.017). In patients with normal EFs, multivariate Cox regression analysis showed that large LV end-systolic dimension and low plasma hemoglobin level were independent predictors of postsurgical mortality. Receiver-operating characteristic analysis showed that LV end-systolic dimension ≥45 mm and hemoglobin level <13.4 g/dl were the best cut-off values for postoperative mortality. In conclusion, preoperative LV end-systolic dimension and hemoglobin level are independent prognostic factors of survival after aortic valve surgery in patients with chronic severe AR and normal LV EFs.

Myocardial deformation abnormalities in patients with aortic regurgitation: a strain rate imaging study

AIMS

Early left ventricular (LV) dysfunction in asymptomatic patients with severe aortic regurgitation (AR) may go undetected due to the lack of a sufficiently sensitive diagnostic tool. Ultrasonic strain/strain rate (S/SR) imaging should now provide such sensitivity in detecting early dysfunction in regional LV systolic deformation. The aim of this study was to understand and define the changes in LV regional systolic deformation based on S/SR imaging in patients with asymptomatic or minimally symptomatic AR.

METHODS AND RESULTS

Eighty-one individuals were studied: 59 asymptomatic patients with isolated non-ischaemic AR who were divided into three sub-groups such as mild, moderate, and severe AR and 22 age-matched healthy subjects. All patients underwent standard echocardiographic examinations including a tissue Doppler imaging study. For LV radial deformation, the posterior wall (LVPW) was examined. To assess LV longitudinal deformation, S and SR data were acquired from the LV lateral wall and septum. Radial as well as longitudinal peak systolic SRs were significantly decreased in patients with both moderate AR (LVPW, P=0.0009; septum, P=0.03; LV lateral wall, P=0.0009) and severe AR (P<0.0001) compared with healthy subjects. Changes in regional LV deformation correlated inversely both with LV end-diastolic volume and with end-systolic volume.

CONCLUSIONS

Strain rate imaging is a sensitive tool in detecting the spectrum of changes in radial and longitudinal deformation in asymptomatic or minimally symptomatic patients with AR. The index where volume was corrected by deformation should form the basis for predicting subclinical LV dysfunction in patients with increasing LV dilatation.

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.

Timing of aortic valve replacement in elderly patients with symptomatic aortic valve disease using outpatient clinical parameters

OBJECTIVE

To determine by how far worsening outpatient clinical parameters can affect outcome after aortic valve replacement, in patients with preserved left ventricular function and symptomatic aortic valve disease.

PATIENTS AND METHODS

Five hundred patients with aortic valve disease underwent aortic valve replacement using a bioprosthesis. In 348 patients, another procedure was added. The preoperative outpatient parameters were investigated for their effect on hospital and long-term mortality. A Fisher exact, Kaplan-Meier univariate and Cox proportional hazard analysis were used.

RESULTS

A retrospective follow-up of 2022 patient years was obtained. Five preoperative parameters were found to be more present in patients with a decreased left ventricular function: 1) severity of symptoms, 2) previous myocardial infarction, 3) conduction defects, 4) aortic valve regurgitation and 5) increasing need for medication. In patients with an ejection fraction of 50% or more, logistic regression analysis showed that hospital mortality increased with need for medication (p=0.004), previously performed CABG (0.015), increase in symptoms (p=0.018) and myocardial infarction (p=0.034). A Kaplan-Meier analysis revealed aortic valve regurgitation (p=0.017) and increased need for medication (p=0.012) as significant on long-term survival. Presence of a previous myocardial infarction showed a trend (p=0.062). A Cox' proportional hazard analysis showed for global mortality increased need for medication (p=0.010) and previous myocardial infarction (p=0.018) as independent factors and for long-term mortality, this was aortic valve regurgitation (p=0.001).

CONCLUSIONS

Results after aortic valve replacement deteriorate with the presence of valve regurgitation, a preoperative myocardial infarction, increasing need for medication or severity of symptoms, even for an ejection fraction of 50% or more. Anamnesis with special care to the degree of symptoms and increasing need for medication early in the valve disease could lead to early referral, thereby reducing number of patients with severe symptoms and improving postoperative results.

Are patients with isolated chronic aortic regurgitation operated in time? Analysis of survival data over a decade

BACKGROUND

Patients suffering from chronic isolated aortic regurgitation have a less favorable outcome than patients with aortic stenosis. According to international recommendations, these patients should undergo surgery as soon as left ventricular function begins to deteriorate, that is, surgery is not to be postponed until clinical symptoms become relevant.

HYPOTHESIS

The study was undertaken to evaluate how satisfactory our timing of surgery was, as reflected by survival data.

METHODS

Survival was studied retrospectively in a consecutive series of patients undergoing surgery for chronic isolated aortic regurgitation during a 10-year period in our institution. Results were compared with data from the literature. By excluding patients with aortic aneurysms and acute endocarditis, we formed a homogeneous patient group of 88 subjects.

RESULTS

Thirty-day mortality was 1% and late mortality after a mean follow-up period of 6 years was 11%. Compared with survival data from an earlier study in which the patient population was similar and resided in the same geographic area, the results in our patient group seem to be better. It is noteworthy that despite a strong effort to recommend surgery at an earlier stage of the disease than previously, 35% of the patients had moderate or severe left ventricular dysfunction preoperatively because of late referrals.

CONCLUSION

This stresses the importance of early detection and careful preoperative follow-up with noninvasive methods in patients with aortic regurgitation.

A heart failure specialist's perspective on cardiac surgery for heart failure

Aside from cardiac transplantation, ventricular assist devices, and the total artificial heart, cardiac surgery now also plays a major role in the overall management of the heart failure patient. For patients with heart failure, cardiac surgery has steadily moved from being a predominant rescue procedure (eg, aneursymectomy, rupture repair, transplantation) to surgical interventions that can prevent or delay the progression of cardiac dysfunction and failure; these operations now include coronary artery bypass surgery, ventricular restoration, and valvular repair/replacement. This article discusses the role and impact of these specific surgical interventions in the setting of ventricular dysfunction and heart failure.

Effect of enalapril on left ventricular diameters and exercise capacity in asymptomatic or mildly symptomatic patients with regurgitation secondary to mitral valve prolapse or rheumatic heart disease

The effects of 12 months of therapy were evaluated in 47 mildly symptomatic patients with moderate to severe mitral valve regurgitation; 26 patients received enalapril and 21 received a placebo. Enalapril was associated with a significant reduction in left ventricular diameter and mitral regurgitation volume, with no evidence of change in systolic function indexes. However, enalapril did not hinder progressive aerobic impairment to effort.

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.