Aortic stenosis and aortic regurgitation express different titin isoforms: Differences and relationships with functional and geometric characteristics

Background-Titin represents an important biomechanical sensor which determines compliance and diastolic/ systolic function of the left ventricle (LV). To assess the different titin-isoform expression and the relationships with functional and geometric patterns, we analyzed titin-isoform expression and cardiomyocytes contractile functioninmyocardialbiopsysamplesofpatientsundergoingaorticvalvereplacement(AVR)foraorticstenosis (AS)and for aorticregurgitation (AR). Method-Specimens,collectedfromtheLVof35withASand35withARundergoingAVRwereanalyzedfortitinisoform expression and cardiomyocytes force measurement. Ten donor hearts were analyzed as controls for normal values. Results were implemented with preoperative geometry and function assessed by Doppler echocardiography. Results-Comparedtocontrols,N2BA/N2Btitin-isoformsratiowasreducedto0.24inAS(p b 0.001)butincreased to 0.51 in AR (p b 0.001). N2BA/N2B titin-isoforms ratio was further reduced in 8 patients with severe (restrictive) diastolic dysfunction (0.17 ± 0.03, p b 0.001) but was increased in patients with severe systolic dysfunction (0.58 ± 0.07, p b 0.001). As compared to controls, Fpasive was higher in AS (6.7 ± 0.2 vs 4.4 ± 0.4kN/m2,p b 0.001)butwaslowerinAR(3.7±0.2vs4.4±0.4kN/m2,p b 0.001).Totalforcewascomparable. FpassivewassignificantlyhigherinAS patientswithseverethanwithmoderateLVdiastolicdysfunction(7.1± 0.5 vs 6.6.±0.6,p=0.004). Conclusions-titin-isoform expression differs in AS and AR as adaptive response to different pathophysiologic scenarios. Co-expressing isoforms at varying ratios results in modulation of the passive mechanical behavior of the LV at different degree of dysfunction and allows for compensative adjustment of the diastolic/systolic properties of the myocardium

CORONARY PERFUSION:IMPACT OF FLOW DYNAMICS AND GEOMETRIC DESIGN OF TWO DIFFERENT AORTIC PROSTHESES OF SIMILAR SIZE

BackgroundAortic valve replacement leads to improvement of coronary flow but not to complete normalization. Coronary hypoperfusion contributes to higher left ventricular mass persistence, arrhythmias, congestive heart failure and sudden death. This prospective study compares 2 similarly sized aortic prostheses (mechanical and porcine) regarding coronary flow and hemodynamic performances in patients who underwent surgery for pure aortic stenosis.MethodsSixty patients having undergone aortic valve replacement for pure aortic stenosis with Medtronic Mosaic Ultra bioprosthesis 21 mm (n = 30) or St Jude Regent mechanical valve 19 mm (n = 30) were evaluated preoperatively and 12 months postoperatively comparing the coronary flow and the hemodynamic behavior. Echocardiography and cardiac positron emission tomography were performed at rest and during exercise or adenosine maximal stimulation, respectively.ResultsThe St Jude Regent mechanical valve, compared with the Medtronic Mosaic Ultra bioprosthesis, had reduced coronary flow reserve (2.1 ± 0.3 vs 2.3 ± 0.2; P = .003), less favorable systolic/diastolic time ratio (0.87 ± 0.02 vs 0.78 ± 0.03; P < .001), and higher mean transprosthetic gradient (46 ± 11 vs 38 ± 9; P = .003) during exercise. Multivariate analysis of impaired coronary reserve related indexed effective orifice area less than 0.65 cm/m2 (risk ratio [RR], 1.9; 95% confidence intervals [CI], 1.5-2.8; P < .001), mechanical valve (RR, 2.5; 95% CI, 1.7-3.3; P < .001), and systolic/diastolic time ratio greater than 0.75 (RR, 2.6; 95% CI, 1.8-3.8; P < .001), as well as high transprosthetic gradient (RR, 1.7; 95% CI, 1.3-2.4; P < .001) ) during exercise with coronary reserve less than 2.2.ConclusionsImprovement 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

Laparoscopic drainage of an ovarian haematoma in a Martina Franca jenny (Equus asinus)

An 11-year-old Martina Franca jenny (Equus Asinus), involved in a breed recovery programme organised by the Puglia Region, was referred to the University’s Veterinary Teaching Hospital for a mass formation detected on the surface of the right ovary. The subject had regular oestrous cycles, but gestation loss was reported in the anamnesis. The ovarian mass was monitored by transrectal palpation and ultrasonography. In the differential diagnosis, an ovarian haematoma, a haemorrhagic anovulatory follicle and a granulosa cell tumour were hypothesised; a surgical resolution with laparoscopic access was chosen. During surgery, about 750 ml of haemorrhagic fluid was drained, confirming the suspect of the ovarian haematoma. After resolution, the jenny was inseminated, eventually giving birth to a live and viable foal. Usually, an ovarian haematoma spontaneously regresses, but, in this report, the lesion remained stable for more than two months, leading to the decision of the surgical resolution. Furthermore, to the authors’ knowledge, this lesion has never been reported in donkeys

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.

Objectives: Left ventricular (LV) diastolic dysfunction after aortic valve replacement (AVR) carries a substantial risk of development of heart failure and reduced survival. In addition to echocardiography, B-type natriuretic peptide (BNP) provides a powerful incremental assessment of diastolic function. This study evaluates BNP as a marker of LV diastolic dysfunction in a cohort of patients with preserved LV ejection fraction who underwent AVR for pure aortic stenosis and the relationship between BNP values and the grade of LV diastolic dysfunction. Methods A total of 113 patients were included in the study. Echocardiographic evaluation was performed preoperatively, 5 days postoperatively and at 12-month follow-up, to assess LV dimensional and functional parameters. Diastolic function was labelled as normal, mild, moderate or severe dysfunction. Concomitantly, BNP levels were evaluated. Results Mild to severe diastolic dysfunction occurred preoperatively in all patients. At 12-month follow-up, 65 (62.5%) patients had mild and 25 (24.1%) moderate to severe diastolic dysfunction. BNP values, categorized for quartile distribution, correlated with diastolic dysfunction grade (P < 0.001 for each comparison). At receiver operating characteristic analysis, the BNP level of 120 pg/ml was 91% sensitive and 85% specific for diastolic disease, while 300 pg/ml was 80% sensitive and 91% specific for moderate or severe diastolic dysfunction. Twelve months after AVR, BNP values were strongly correlated with the significant echocardiographic parameters suggestive of diastolic dysfunction (P ≤ 0.006 in all cases). Conclusions The BNP level following AVR is related to diastolic disease severity and may complement echocardiographic evaluation when symptoms are unclear and LV function is difficult to interpret