Normalization of left ventricular dimensions after Ross operation with aortic annular reduction

Comparative evaluation of left ventricular mass regression after aortic valve replacement: a prospective randomized analysis

BACKGROUND

We assessed the hemodynamic performance of various prostheses and the clinical outcomes after aortic valve replacement, in different age groups.

METHODS

One-hundred-and-twenty patients with isolated aortic valve stenosis were included in this prospective randomized randomised trial and allocated in three age-groups to receive either pulmonary autograft (PA, n = 20) or mechanical prosthesis (MP, Edwards Mira n = 20) in group 1 (age < 55 years), either stentless bioprosthesis (CE Prima Plus n = 20) or MP (Edwards Mira n = 20) in group 2 (age 55-75 years) and either stentless (CE Prima Plus n = 20) or stented bioprosthesis (CE Perimount n = 20) in group 3 (age > 75). Clinical outcomes and hemodynamic performance were evaluated at discharge, six months and one year.

RESULTS

In group 1, patients with PA had significantly lower mean gradients than the MP (2.6 vs. 10.9 mmHg, p = 0.0005) with comparable left ventricular mass regression (LVMR). Morbidity included 1 stroke in the PA population and 1 gastrointestinal bleeding in the MP subgroup. In group 2, mean gradients did not differ significantly between both populations (7.0 vs. 8.9 mmHg, p = 0.81). The rate of LVMR and EF were comparable at 12 months; each group with one mortality. Morbidity included 1 stroke and 1 gastrointestinal bleeding in the stentless and 3 bleeding complications in the MP group. In group 3, mean gradients did not differ significantly (7.8 vs 6.5 mmHg, p = 0.06). Postoperative EF and LVMR were comparable. There were 3 deaths in the stented group and no mortality in the stentless group. Morbidity included 1 endocarditis and 1 stroke in the stentless compared to 1 endocarditis, 1 stroke and one pulmonary embolism in the stented group.

CONCLUSIONS

Clinical outcomes justify valve replacement with either valve substitute in the respective age groups. The PA hemodynamically outperformed the MPs. Stentless valves however, did not demonstrate significantly superior hemodynamics or outcomes in comparison to stented bioprosthesis or MPs.

LV reverse remodeling imparted by aortic valve replacement for severe aortic stenosis; is it durable? A cardiovascular MRI study sponsored by the American Heart Association

BACKGROUND

In patients with severe aortic stenosis (AS), long-term data tracking surgically induced effects of afterload reduction on reverse LV remodeling are not available. Echocardiographic data is available short term, but in limited fashion beyond one year. Cardiovascular MRI (CMR) offers the ability to serially track changes in LV metrics with small numbers due to its inherent high spatial resolution and low variability.

HYPOTHESIS

We hypothesize that changes in LV structure and function following aortic valve replacement (AVR) are detectable by CMR and once triggered by AVR, continue for an extended period.

METHODS

Twenty-four patients of which ten (67 ± 12 years, 6 female) with severe, but compensated AS underwent CMR pre-AVR, 6 months, 1 year and up to 4 years post-AVR. 3D LV mass index, volumetrics, LV geometry, and EF were measured.

RESULTS

All patients survived AVR and underwent CMR 4 serial CMR's. LVMI markedly decreased by 6 months (157 ± 42 to 134 ± 32 g/m2, p < 0.005) and continued trending downwards through 4 years (127 ± 32 g/m2). Similarly, EF increased pre to post-AVR (55 ± 22 to 65 ± 11%,(p < 0.05)) and continued trending upwards, remaining stable through years 1-4 (66 ± 11 vs. 65 ± 9%). LVEDVI, initially high pre-AVR, decreased post-AVR (83 ± 30 to 68 ± 11 ml/m2, p < 0.05) trending even lower by year 4 (66 ± 10 ml/m2). LV stroke volume increased rapidly from pre to post-AVR (40 ± 11 to 44 ± 7 ml, p < 0.05) continuing to increase non-significantly through 4 years (49 ± 14 ml) with these LV metrics paralleling improvements in NYHA. However, LVmass/volume, a 3D measure of LV geometry, remained unchanged over 4 years.

CONCLUSION

After initial beneficial effects imparted by AVR in severe AS patients, there are, as expected, marked improvements in LV reverse remodeling. Via CMR, surgically induced benefits to LV structure and function are durable and, unexpectedly express continued, albeit markedly incomplete improvement through 4 years post-AVR concordant with sustained improved clinical status. This supports down-regulation of both mRNA and MMP activity acutely with robust suppression long term.

Midterm outcomes and predictors of reintervention after the Ross procedure in infants, children, and young adults

OBJECTIVES

This study assessed the type, time course, and risk factors for right and left ventricular outflow tract reinterventions after the Ross procedure in a population of infants, children, and young adults.

METHODS

Patients who underwent the Ross procedure between January 1995 and June 2004 were included (n = 121 consecutive patients). Kaplan-Meier and hazard analyses of right and left ventricular outflow tract reinterventions were performed, and predictors of reintervention were identified through multivariate analysis.

RESULTS

The median age at the Ross procedure was 8.2 years (4 days to 34 years); 20% were aged less than 1 year. Half of the patients had isolated aortic valve disease; the other half had complex left-sided heart disease. Early mortality (<30 days) was 2.5% (n = 3). There were 2 late deaths (1.7%). Follow-up (median 6.5 years [2.5 months to 10.4 years]) was available for 96% of survivors (n = 111). Right ventricular outflow tract reintervention (n = 22 in 15 patients) was performed 2.0 years (2.0 weeks to 9.8 years) after the Ross procedure because of stenosis in 19 of 22 cases. Freedom from right ventricular outflow tract reintervention at 8 years was 81%. Smaller homograft size was the strongest predictor (P < .001) of right ventricular outflow tract reintervention. Left ventricular outflow tract reintervention (n = 15 in 15 patients) was performed 2.8 years (1.0 months to 11.6 years) after the Ross procedure because of severe neoaortic insufficiency in 10 of 15 patients. Freedom from left ventricular outflow tract reintervention at 8 years was 83%. Native pulmonary valve abnormalities (P < .01), original diagnosis of aortic insufficiency (P < .01), prior aortic valve replacement (P = .01), and prior ventricular septal defect repair (P = .04) predicted left ventricular outflow tract reintervention.

CONCLUSIONS

At midterm follow-up after the Ross procedure, interim mortality is rare. Neoaortic insufficiency and right ventricle to pulmonary artery conduit obstruction are common postoperative sequelae, requiring reintervention in one quarter of patients.

Is the Ross procedure as good as we thought it would be?

For patients requiring intervention because of progressive disease of the aortic valve, the perfect palliation will provide a valve that produces normal dynamics of flow, will not require anti-coagulation, will grow with the patient, and have long term durability. Current surgical interventions include aortic valvoplasty, or replacement with either a mechanical or tissue prosthesis. Options for tissue valves include insertion of a pulmonary autograft in the Ross procedure, a cadaveric homograft, or porcine or bovine xenograft valves. The optimal option is still debated.

Current Perspective on Aortic Valve Repair and Valve-Sparing Aortic Root Replacement

Aortic valve repair and valve-sparing aortic root replacement are attractive concepts because they offer the possibility of valve competence without structural deterioration due to nonviability and they preclude the need for anticoagulation. Enthusiasm for aortic valve repair has waxed and waned over the past 45 years due in part to the inherent technical difficulties and poor mid-term results. Renewed interest in the concept of aortic valve repair has paralleled the development of valve-sparing aortic root replacement over the last 20 years. A current perspective on aortic valve repair and valve-sparing aortic root replacement is presented in the following review. Historical background, indications for repair, technical considerations, and outcomes data are discussed.

Do pulmonary autografts provide better outcomes than mechanical valves? A prospective randomized trial

BACKGROUND

The objective of this study was to compare the performance of pulmonary autografts with mechanical aortic valves, in the treatment of aortic valve stenosis.

METHODS

Forty patients with aortic valve stenoses, and below the age of 55 years, were randomly assigned to receive either pulmonary autografts (n = 20) or mechanical valve (Edwards MIRA; Edwards Lifesciences, Irvine, CA) prostheses (n = 20). Clinical outcomes, left ventricular mass regression, effective orifice area, ejection fraction, and mean gradients were evaluated at discharge, 6 months, and one year after surgery. Follow-up was complete for all patients.

RESULTS

Hemodynamic performance was significantly better in the Ross group (mean gradient 2.6 mm Hg vs 10.9 mm Hg, p = 0.0005). Overall, a significant decrease in left ventricular mass was found one year postoperatively. However, there was no significant difference in the rate and extent of regression between the groups. There was one stroke in the Ross group and one major bleeding complication in the mechanical valve group. Both patients recovered fully.

CONCLUSIONS

In our randomized cohort of young patients with aortic valve stenoses, the Ross procedure was superior to the mechanical prostheses with regard to hemodynamic performance. However, this did not result in an accelerated left ventricular mass regression. Clinical advantages like reduced valve-related complications and lesser myocardial strain will have to be proven in the long term.

Aortic Valve Replacement for Aortic Insufficiency: Valve Type as a Determinant of Systolic Strain Recovery

BACKGROUND AND AIM

Left ventricular (LV) 3D systolic strain decreases in absolute value postoperatively and does not recover in patients who undergo aortic valve replacement (AVR) for chronic aortic insufficiency (AI). We investigated whether choice of valve prosthesis (mechanical [St. Jude], bioprosthetic [bovine pericardial], Ross procedure) had a significant impact on strain recovery in this surgical population.

METHODS

MRI with tissue-tagging was performed on 14 patients with chronic AI both before and 28 +/- 13 months after AVR. Average values of LV systolic strain and end-systolic stress (ESS) were computed from MRI data for the LV. Three types of prosthetic valve were examined (Ross procedure n = 4, bovine pericardial n = 5, and St. Jude n = 5).

RESULTS

Overall, systolic strain, ESS, LV volumes, ejection fraction, and LV mass all changed significantly following AVR. Comparisons between individual valve types revealed no differences in any of these measurements. Patients who received a mechanical valve had a greater decrease in the absolute value of systolic strain following surgery compared to patients from the nonmechanical group (Ross procedure and bioprosthetic valve). Comparisons between the Ross group and the prosthetic group (St. Jude and bioprosthetic) produced no significant differences in strain, ESS, LV volume, and mass.

CONCLUSIONS

These early results suggest that valve prosthetic type may be a factor in efforts to improve strain recovery after AVR for AI, although further investigation is warranted. MRI with tissue-tagging may be a useful tool for comparing the impact of prosthetic valve choice on incompletely recovered systolic strain following AVR for chronic AI.

Advances in pediatric cardiovascular surgery: anatomic reconstruction of the left ventricular outflow tract in transposition of the great arteries with pulmonic valve abnormalities

In the past years, advances in pediatric cardiovascular surgery have occurred in many areas with some of the greatest strides being made in complex repairs in younger age groups. Aggressive early corrections while higher risk, may in the long run provide a child with a normal anatomic heart, and corresponding myocardial growth and physiology.