Since the 1950s more than 80 models of prosthetic heart valves have been developed and used. More than 60,000 valve replacements are performed annually in the United States. Prosthetic heart valves may be mechanical or bioprosthetic. Mechanical valves, which are composed primarily of metal or carbon alloys, are classified according to their structure as caged-ball, single-tilting-disk, or bileaflet-tilting-disk valves. Bioprostheses may be heterografts, which are composed of porcine or bovine tissue (pericardial or valvular) mounted on a metal support, or homografts, which are preserved human aortic valves. The most commonly used prosthetic valves are listed in Table 1 and illustrated in Figure 1. . . .

Prosthetic heart valves

OBJECTIVE: To assess the prevalence, mechanisms, and significance of paraprosthetic regurgitation detected incidentally by transoesophageal echocardiography (TOE) in patients after heart valve replacement.
DESIGN: Prospective observational study.
SETTING: Tertiary referral centre.
PATIENTS: 360 consecutive patients (mean (SD) age 65.8(9.5) years, 193 women) undergoing elective first ever valve replacement.
METHODS: Postoperative and follow up TOE, and tests for haemolysis and anaemia.
RESULTS: There were 243 aortic, 90 mitral, and 27 double valve replacements, using 316 mechanical and 44 tissue valves, giving 270 aortic and 117 mitral valves. One patient with severe paraprosthetic mitral regurgitation underwent immediate reoperation and was excluded from subsequent analyses. Paraprosthetic jets were detected around 16 (6%) of the aortic and 38 (32%) of the mitral valves (p < 0.05) at the postoperative study. Follow up TOE was available for 151 aortic and 67 mitral valves, 0.9 (0.5) years after operation. Paraprosthetic jets were present in 15 (10%) of the aortic and 10 (15%) of the mitral valves (NS). Two thirds of the aortic and a fifth of the mitral jets were new. Paraprosthetic jets were more common in aortic valves in a supra-annular (12 of 88, 14%) than in an intra-annular position (4 or 182, 2%; p < 0.005) and in mitral valves inserted with continuous (36 of 88, 41%) rather than interrupted sutures (2 of 28, 7%; p < 0.001). Lactate dehydrogenase concentration was higher in patients with paraprosthetic jets than in those without (752 (236) v 654 (208) IU/l, p < 0.001). Haemoglobin and haptoglobin concentrations were not different.
CONCLUSIONS: Small paraprosthetic leaks are common, are related to surgical factors, are not associated with increased subclinical haemolysis, and are benign during the first year after heart valve replacement.

https://heart.bmj.com/content/heartjnl/89/11/1316.full.pdf

Prevalence and clinical significance of incidental paraprosthetic valvar regurgitation: a prospective study using transoesophageal echocardiography.

Clinical outcomes in patients undergoing percutaneous closure of periprosthetic paravalvular leaks.

Background: Following mitral valve replacement, surgical closure of paravalvular leaks is usually advised in severely symptomatic patients and in those requiring blood transfusions for persisting haemolysis. However, the long-term prognosis of less symptomatic patients or those not needing blood transfusions is unknown. Methods: Between 1987 and 1997, we observed 96 patients with mitral paravalvular leakage. A paraprosthetic leak was diagnosed after a median time of 119 days (range: 1 day‐23 years) after primary mitral valve replacement. During an average follow-up of 5 years (range: 1‐23 years), 50/96 patients were referred for surgical closure. Results: Compared with patients who received conservative treatment, those referred for surgery had a significantly lower mean preoperative haematocrit (Pa 0:002) with a higher proportion of patients being in the NYHA class III/IV (Pa 0:03). Age, gender, left ventricular function and number and size of leaks did not differ between the groups. The 30-day postoperative mortality for valve reoperation was 6% (3/50); during follow-up three further patients died, resulting in an overall mortality rate of 12%. In the group treated conservatively there was a mortality rate of 26% (12/ 46). Thus, the actuarial survival for patients referred for surgery was 98, 90 and 88% after 1, 5 and 10 years, compared with 90, 75 and 68% for patients treated conservatively (long-rank Pa 0:03). In addition, there was a significant increase in mean haematocrit levels (Pa 0:0001) and an improvement in NYHA class III/IV symptoms (Pa 0:002), vertigo (Pa 0:001) and fatigue (Pa 0:001) after surgery. Conclusions: Following mitral valve replacement, a more aggressive surgical treatment is recommended for patients with paraprosthetic leaks. Surgery should be offered to less symptomatic patients, as well as those not requiring blood transfusion. q 2000 Elsevier Science B.V. All rights reserved.

https://www.zora.uzh.ch/id/eprint/113298/1/17-1-14.pdf

Paravalvular leakage after mitral valve replacement: improved long-term survival with aggressive surgery?

Acetyl-coenzyme A synthetase (AMP forming; Acs) is an enzyme whose activity is central to the metabolism of prokaryotic and eukaryotic cells. The physiological role of this enzyme is to activate acetate to acetyl-coenzyme A (Ac-CoA). The importance of Acs has been recognized for decades, since it provides the cell the two-carbon metabolite used in many anabolic and energy generation processes. In the last decade researchers have learned how carefully the cell monitors the synthesis and activity of this enzyme. In eukaryotes and prokaryotes, complex regulatory systems control acs gene expression as a function carbon flux, with a second layer of regulation exerted posttranslationally by the NAD+/sirtuin-dependent protein acetylation/deacetylation system. Recent structural work provides snapshots of the dramatic conformational changes Acs undergoes during catalysis. Future work on the regulation of acs gene expression will expand our understanding of metabolic integration, while structure/function studies will reveal more details of the function of this splendid molecular machine.

Acetyl-coenzyme A synthetase (AMP forming)

Paraprosthetic leak (PPL) is a rare but potentially serious complication of cardiac valve replacement. Between 1974 and 1988, 1175 prosthetic valves were implanted in 1026 patients by one cardiac surgeon at St. Thomas' Hospital, London. Of these 539 (52.5%) were aortic (AVR), 334 (32.6%) mitral (MVR), 7 (0.7%) tricuspid, and 144 (14%) AV and MV double valve replacements (DVR). There were only 2 triple valve replacements. The prosthetic valves implanted were the Starr-Edwards (7%), Bjork Shiley (11.8%), Lillehei-Kaster (23%), Carpentier-Edwards bioprosthesis (35.2%), Duromedics bileaflet (16.4%) and a variety of other mechanical and bioprosthetic valves (6.6%). Over the 15 year period there were a total of 82 (7%) valve failures of which PPL was diagnosed in 29 (2.5%) valves in 24 patients. Presenting features included cardiac decompensation in 72%, bacterial endocarditis in 12% and haemolytic anaemia in 12%. One patient (4%) had no symptoms. Nineteen patients underwent re-operation. Median time to re-operation was 15 months (range 1-65 months) with a re-operative mortality of 22%. Clinical evidence of prosthetic valve infection was found in 79% of MVR and 67% of AVR. A heavily calcified aortic annulus, found in 47% of patients, may also have contributed to PPL after AVR.

Neville Em

Papers

Paraprosthetic leak: a complication of cardiac valve replacement.