In patients with concomitant aortic and mitral valve disease is aortic valve replacement with mitral valve repair superior to double valve replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in patients with concomitant aortic and mitral valve disease is aortic valve replacement with mitral valve plasty (MVP) superior to double valve replacement (DVR) in terms of improved long-term survival? Altogether 156 papers were found using the reported search, of which seven represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Out of seven papers, that simultaneously compare these two treatment modalities, three favor MVP combined with aortic valve replacement (AVR) over DVR, two papers advocate the opposite and two failed to find any significant difference in long-term survival, freedom from reoperation and thromboembolic and bleeding complications between these two surgical options. All data presented derive from level 2b evidence. Critical appraisal of these studies is constricted by the large heterogeneity of the patients, diversity in treatment protocols and inherent selection bias. We conclude that currently the available evidence is insufficient to prove that AVR with MVP is superior to DVR in patients with double valve disease.     

Is prophylactic aortic valve replacement indicated during mitral valve surgery for mild to moderate aortic valve disease?

BACKGROUND: Determining the need for surgical treatment of coexisting mild to moderate aortic valve disease in patients referred for mitral valve surgery is often difficult. The purpose of this study was to assess long-term clinical outcome and the need for subsequent aortic valve replacement in patients with mild to moderate rheumatic aortic valve disease at the time of mitral valve surgery. METHODS: A total of 275 patients (90 men and 185 women, mean age 43 years) with rheumatic disease who underwent mitral valve surgery were followed up for an average of 9 years. Patients were classified into two groups: those with coexisting mild to moderate aortic valve disease at the time of mitral valve surgery (141 patients, group A) and those without (134 patients, group B). Primary outcomes (death and subsequent aortic valve surgery) were compared between the two groups. RESULTS: At the time of mitral valve surgery, 104 patients (74%) in group A had mild aortic regurgitation, 37 (26%) had moderate aortic regurgitation, 5 had (4%) mild aortic stenosis, and 2 (1%) had moderate aortic stenosis. At the end of follow-up, no patient had severe aortic valve disease. In all, 12 patients (5%) in group A had primary events (eight deaths and four subsequent aortic valve replacements), and 12 patients (9%) in group B had such events (12 deaths). According to Kaplan-Meier analysis, neither the survival rate nor the event-free survival rate differed significantly over the follow-up period between the two groups. CONCLUSIONS: In most patients who have mild to moderate rheumatic aortic valve disease at the time of mitral valve surgery, the long-term outcome is comparable to that of subjects without aortic valve disease at the time of mitral valve surgery. Subsequent aortic valve replacement is rarely needed after a long follow-up period.     

Is repair of aortic valve regurgitation a safe alternative to valve replacement?

OBJECTIVE: To assess outcome of valve repair in patients with aortic valve regurgitation with emphasis on incidence and risk of reoperation. METHODS: We retrospectively reviewed 160 consecutive patients (127 men) who underwent aortic valve repair between 1986 and 2001. Ages ranged from 14 to 84 years (mean 55 +/- 17 years). Patients were categorized according to the main etiology of valve disease; 63 patients (39%) had annular dilation leading to central leakage, 54 (34%) had bicuspid valve, 34 (21%) with tricuspid valve had cusp prolapse, and 9 (6%) had cusp perforation. Repair methods included commissural plication (n = 154, 96%), partial cusp resection with plication (n = 47, 29%), resuspension or cusp shortening (n = 44, 28%), and closure of cusp perforation (n = 10, 6%). RESULTS: There was 1 early death (0.6%). Two patients required re-repair of the aortic valve during initial hospitalization. During a mean follow-up of 4.2 years, there were 16 late deaths. Overall, 16 of 159 hospital survivors had late reoperation on the aortic valve (mean interval 2.8 years) without early mortality. Risks of reoperation on the aortic valve were 9%, 11%, and 15% at 3, 5, and 7 years, respectively. CONCLUSIONS: Aortic valve repair can be performed with low risk and excellent freedom from valve-related morbidity and mortality. Late recurrence of aortic valve regurgitation led to reoperation in 8.8% of patients, but mortality associated with subsequent procedures is low. Aortic valve repair appears to be a good option for selected patients, particularly young patients who wish to avoid chronic anticoagulation with warfarin.     

Should the tricuspid valve be replaced with a mechanical or biological valve?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether patients requiring tricuspid replacement should have a mechanical or a biological valve. Using the reported search, 561 papers were identified. Thirteen papers represented the best evidence on the subject. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, weaknesses, results and study comments were tabulated. We conclude that there are no major differences between the insertion of a mechanical or biological tricuspid valve. Aggregating the available data it is found that the reoperation rate is similar with bioprosthetic degeneration rate being equivalent to the mechanical thrombosis rate. Conversely up to 95% of patients with a bioprosthesis still receive anticoagulation. Survival in over 1000 prostheses pooled by meta-analysis was equivalent between biological and mechanical valves.     

Is the valve OK or not? Immediate evaluation of a replaced aortic valve

Transesophageal echocardiography is a crucial tool in intraoperative evaluation of newly implanted/repaired heart valves because suspected valvular malfunction needs to be identified and sometimes surgically corrected. Although color Doppler is often adequate in evaluating the expected regurgitant jets, as well as excluding pathologic paravalvular leaks, spectral Doppler techniques are the most commonly used methods for estimating transvalvular gradients in the operating room. However, these methods are subject to a variety of confounding factors, including subvalvular gradients and pressure recovery. Other methods of valve area estimation should also be used when evaluating a prostethic aortic valve, including the continuity equation and the left ventricular outflow tract/aortic valve velocity ratio.     

Is a stentless aortic valve superior to conventional bioprosthetic valves for aortic valve replacement?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether a stentless valve is superior to conventional stented valves when tissue aortic valve replacement is performed. Altogether more than 515 papers were found using the reported search, of which 16 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that stentless valves allow a larger effective orifice area valve to be implanted with a lower mean and peak aortic gradient postoperatively. At six months several studies and a meta-analysis have shown superior left ventricular mass regression in the stentless valve groups. However, by 12 months the stented valve groups catch up in terms of mass regression and this significance disappears. So the 'eminent speaker from the floor', was right with his statement, that there have been no definitively proven benefits for stentless valves.     

Strut fracture of Bj?rk-Shiley convexo-concave valve in Japan--risk of small valve size--.

BACKGROUND: The Bj?rk-Shiley convexo-concave (BSCC) prosthetic valve was introduced in 1979. Between 1979 and 1986, approximately 86,000 BSCC valves were implanted. By December 31, 1994, 564 complete strut fractures had been reported to the manufacture. We experienced a case of an outlet strut fracture and investigated the risk of BSCC prosthetic valve fractures in Japan. METHODS AND RESULTS: To investigate the risk factor of a strut fracture in Japan, we investigated published cases of strut fractures. Between 1979 and 1986, 2021 BSCC valves were implanted in Japan. By January 31, 2000, 11 complete strut fractures of 60-degree BSCC valves including our case had occurred. The patients were eight males and three females. The average age at valve replacement was 42.4+/-8.1 years, and nine of eleven (81.8%) were patients < 50 years-old. The average age of the patients when the BSCC valve fractured was 47.7+/-6.4 years, and eight of eleven (72.7%) were patients <= 50 years old. All patients were implanted in the mitral position. The sizes of the BSCC valve were 27 mm (n=5) (45.5%), 29 mm (n=3) (27.2%), and 31 mm (n=3) (27.2%). Four patients died and seven patients survived. CONCLUSIONS: Although only 11 BSCC valve struts fractured and statistical analysis could not be performed, our findings suggest that the high risk group for a strut fracture in Japan is young male patients with a mitral valve, >= 27 mm in size with BSCC models manufactured before March 1982. When following-up patients with BSCC models manufactured before March 1982, the possibility of a strut fracture in all BSCC valve sizes should be kept in mind.     

Progression of aortic valve stenosis: TGF-β1 is present in calcified aortic valve cusps and promotes aortic valve interstitial cell calcification via apoptosis

Background

Aortic valve stenosis characteristically progresses due to cuspal calcification, often necessitating valve replacement surgery. The present study investigated the hypothesis that TGF-β1, a cytokine that causes calcification of vascular smooth muscle cells in culture, initiates apoptosis of valvular interstitial cells as a mechanistic event in cuspal calcification.

Methods

Noncalcified and calcified human aortic valve cusps were obtained at autopsy or at the time of cardiac surgery. The distributions within cusps of TGF-β1, latent-TGF-β1-associated peptide, and TGF-β receptors were studied using immunohistochemistry. The effects of TGF-β1 on mechanistic events contributing to aortic valve calcification were also investigated using sheep aortic valve interstitial cell (SAVIC) cultures.

Results

Immunohistochemistry studies revealed that calcific aortic stenosis cusps characteristically contained within the extracellular matrix qualitatively higher levels of TGF-β1 than noncalcified cusps. Noncalcified normal valves demonstrated only focal intracellular TGF-β1. Addition of TGF-β1 to SAVIC cultures led to a cascade of events, including: cellular migration, aggregation, formation of apoptotic-alkaline phosphatase enriched nodules, and calcification of these nodules. The time course of these events in the SAVIC culture system was rapid with nodule formation with apoptosis by 72 hours, and calcification after 7 days. Furthermore, ZVAD-FMK, an antiapoptosis agent (caspase inhibitor), significantly inhibited calcification and apoptosis induced by TGF-β1, but had no effect on nodule formation. However, cytochalasin D, an actin-depolymerizing agent, inhibited nodule formation, but not calcification.

Conclusions

TGF-β1 is characteristically present within calcific aortic stenosis cusps, and mediates the calcification of aortic valve interstitial cells in culture through mechanisms involving apoptosis.     

Pyelovenous backflow or veno-caliceal valve fistula?

A 70-year-old male with urinary bladder carcinoma was admitted for follow-up. Retrograde pyelography demonstrated transfer of contrast medium into the left renal vein in two independent sessions. The absence of hematuria and a negative CT scan ruled out a classical veno-caliceal fistula. The presence of a veno-caliceal valve fistula into the left renal vein was hypothesized.