Coronary perfusion: Impact of flow dynamics and geometric design of 2 different aortic prostheses of similar size

Abstract

Improvement of coronary flow and reserve was more evident for bioprostheses than for mechanical valves. The bioprostheses demonstrated superior hemodynamics during exercise, which may have some impact on exercise capability during normal daily life.

B-type natriuretic peptide as a biochemical marker of left ventricular diastolic function: assessment in asymptomatic patients 1 year after valve replacement for aortic stenosis

“…The results can be summarized as follows: (i) BNP levels were higher before operation in patients undergoing AVR for pure AS despite relatively preserved LVEF; (ii) early after operation, there was a dramatic transient increase in BNP levels; (iii) at 12-month follow-up, BNP levels decreased significantly compared with the preoperative levels, although normal values were reached in only few patients within 12 months; (iv) BNP levels reflected LV diastolic function and its severity also in asymptomatic patients; (v) BNP values >120 pg/ml 12 months after AVR were strongly correlated to echocardiographic findings suggestive of diastolic dysfunction; (vi) BNP values >300 pg/ml were strongly correlated to echocardiographic findings suggestive of moderate or severe diastolic dysfunction. Following AVR, the afterload of the left ventricle is immediately reduced, and this leads to a recovery of wall stress, LV ejection time, LV volume, coronary perfusion and the load of the left atrium [4,17,23]. Conversely, persistence of LV hypertrophy is common after AVR and its regression is a slow process that takes years after correction of the primary haemodynamic abnormality and may continue for decades after surgery [23].…”

“…Further exclusion criteria were all significant causes of elevated or reduced BNP levels other than LV dysfunction as indicated in the current literature: serum creatinine concentration >150 μmol/l, severe pulmonary disease (acute respiratory distress syndrome, lung disease with right heart failure, primary pulmonary hypertension and other causes of pulmonary hypertension) and obesity defined as body mass index (BMI) >30. Concurrent patients complying with the inclusion criteria and receiving mechanical valve substitutes were not enrolled to obtain homogeneity of patient age and postoperative haemodynamic performance (that could influence BNP levels) [3][4]17]. Nevertheless, bioprostheses are not routinely treated with warfarin postoperatively in our department, and thus, a potential effect of warfarin on plasma BNP was avoided.…”

“…Aortic valve replacement (AVR) leads to early postoperative haemodynamic and metabolic recovery, contributing to the improvement in LV function and geometry. A successful AVR often results in persistent LV hypertrophy and/or in LV outflow tract obstruction, which jeopardizes systolic and diastolic function recovery [1][2][3][4]. Persistent LV diastolic dysfunction after AVR, although largely underestimated in the past, has recently been shown to be an independent predictor of hospitalization and mortality [5,6] and to carry a substantial risk of the subsequent development of heart failure also in asymptomatic patients with preserved left ventricular ejection fraction (LVEF) [7].…”

Definition of local and regional recurrence in the American College of Surgery Oncology Group Z0030 trial

“…In a recent study, we evaluated by echocardiography the hemodynamic performance at rest and during exercise of 2 different aortic prostheses of similar size implanted in patients who underwent surgery for pure aortic stenosis. 4 Although the study compared a mechanical valve with a porcine bioprosthesis, our results validated the technical procedures as model for evaluations under stress.…”

“…The American College of Surgery Oncology Group Z0030 trial results continue to produce new findings. 4 We believe the full utilization of this landmark database is important to improve clinical practice and future studies. In a recent publication, Suri and colleagues 1 evaluated the hemodynamic performance of the latest generation of biologic aortic valve prostheses.…”