Diastolic unloading and improved LV pump efficiency early after repair of the insufficient mitral valve.

BACKGROUND: This study aimed to evaluate the acute effect of mitral valve repair (MVR) on LV hemodynamics and geometry in patients with normal ventricular function. METHODS: In 10 patients with severe mitral regurgitation undergoing MVR, pressure-volume relationships were recorded before annuloplasty prior to and after hemodilution and after MVR during stable circulatory condition, using the conductance catheter technique (CC). Analyses were done off-line; volume calibration was based on data obtained after completion of valve repair (mean +/- s.d.). RESULTS: CC showed that only 61 +/- 15 % of left ventricular output was ejected into the systemic circulation, regurgitation volume being 39 +/- 15 %. MVR led to a reduction in LV stroke work index from 4.7 +/- 1.8 mm Hg x l x m (-2) at before valve repair to 2.2 +/- 1.0 mm Hg x l x m (-2) after surgery at unchanged cardiac index. LV diastolic filling parameters improved: LV relaxation time constant tau decreased from 52 +/- 15 to 37 +/- 11 ms and dP/dt (min) increased from - 873 +/- 231 to - 1286 +/- 283 mm Hg x s (-1). CONCLUSIONS: Despite cardioplegic arrest, MVR leads to acute improvement of diastolic LV function early after the operation. This may explain why valve repair has an acute positive effect in patients with impaired LV function.

[End of the millennium - end of the single mammary artery graft? Two internal mammary arteries - standard for the next millennium? Early clinical results and analysis of risk factors in 1487 patients with bilateral internal mammary artery bypass]. / Ende eines Jahrtausends--Ende des Einfach-Mammaria-Bypasses. Zwei Arteriae mammariae internae--Standard für das nächste Jahrtausend? Klinische Ergebnisse und Risikofaktorenanalyse von 1487 Patienten mit bilateralem Arteria mammaria interna Bypass.

OBJECTIVE: CABG with bilateral IMA grafts (BIMA) can improve long-term results in cardiac morbidity and mortality. An enhanced incidence of bleeding and wound complications compared to patients with single IMA (SIMA) remains a matter of debate. The aim of the study was to compare the operative outcomes of patients who had undergone CABG with BIMA and SIMA in situ grafts, especially to identify patient-related risk factors, such as obesity, diabetes mellitus and age above 70 years. METHODS: Out of a total of 5144 patients operated on between January 1996 and September 1999, patients with isolated CABG (n = 3671) with BIMA or SIMA were analyzed retrospectively. In the BIMA group, the patients' (n = 1478) mean age was 64.0 years; mean EF was 62.1%. In the SIMA group (n = 2184), mean age was 65.4 years and mean EF was 60.6% (n.s.). In the BIMA group, the right IMA was led anterior of the aorta to the LAD, the left IMA to the lateral wall. In the SIMA group, the LAD was revascularized with the left IMA. Additional bypasses were performed with vein grafts. RESULTS: The 30-day mortality was 1.6% in the BIMA group, 1.7% in the SIMA group in patients under 70 years, and 4.1% (BIMA) and 4.0% (SIMA) in patients over 70 years (p = n.s.). A significantly higher blood loss was observed in the BIMA group (BIMA 979 +/- 708 ml; SIMA 790 +/- 575 ml; p < 0.05). The rethoracotomy rate due to bleeding was significantly higher in patients with BIMA (4.1%) compared to those with SIMA (2.5%; p < 0.05). In patients with a body mass index (BMI) of less than 27, no significant difference could be found (SIMA 2.8%, BIMA 3.4%; p = n.s.). Patients with a BMI > 27 showed a significantly higher rethoractomy rate (SIMA 2.2%; BIMA 4.9%). A higher incidence of sternal instabilities could be observed in the BIMA group (4.2%; p < 0.05). Diabetes mellitus could not be identified as an independent risk factor for sternal complications (SIMA 2.9%; BIMA 5.0%; p = n.s.). CONCLUSION: CABG using both IMAs can be performed in nearly all patients as a routine method with good clinical results and low mortality. Bleeding in the BIMA group within 48 h was increased. BMI > 27 could be identified as a risk factor for sternal complications, but not diabetes mellitus or age over 70 years.

[Clinical and hemodynamic results of the mosaic bioprosthesis in aortic position]. / Klinische und hämodynamische Ergebnisse der Mosaic Bioprothese in Aortenposition.

INTRODUCTION: Aim of the study was to evaluate the hemodynamic and clinical performance of the Mosaic bioprosthesis in the aortic position. PATIENTS AND METHODS: The Mosaic bioprosthesis is a stented porcine heart valve for implantation in the aortic and mitral position, which combines zero pressure and root pressure fixation with glutaraldehyde, antimineralization treatment with alpha amino oleic acid (AOA) and a low profile stent, to optimize hemodynamic function and to minimize mechanical wear and thus to achieve longer tissue durability. Included in a multicenter study, 100 patients (49 females) underwent isolated aortic valve replacement with the Mosaic bioprosthesis between February 1994 and May 1999. Average age at implant was 73.4 +/- 7.3 years (range 31.3-86.8 years). Preoperative and operative clinical data are shown in Tables 1 and 2. Patients were followed-up within the first 30 postoperative days, after six months and at annual intervals, including transthoracic echocardiography and documentation of any adverse events. Mean follow-up was 3.8 years (range 0.1-7.1 years), total 383.1 patient-years. Follow-up is 100% complete. RESULTS: One year after implantation of the bioprosthesis, mean systolic pressure gradient was 15.3 +/- 6.7 mmHg (21), 14.5 +/- 5.7 mmHg (23), 12.7 +/- 4.1 mmHg (25) and 13.0 +/- 4.8 mmHg (27); effective orifice area (EOA) was 1.4 +/- 0.4 cm2 (21), 1.7 +/- 0.4 cm2 (23), 1.8 +/- 0.4 cm2 (25) and 2.6 +/- 0.4 cm2 (27) (Table 3). One year postoperative, nine patients (10.8%) showed mild aortic regurgitation and one patient (1.2%) moderate. Left ventricular mass index decreased significantly for all sizes within the first postoperative year from 159.7 +/- 56.8 g/m2 to 137.3 +/- 40.8 g/m2. Separating the patients with regard to valve size, only the 21-group (154.1 +/- 51.2 g/m2 to 129.1 +/- 34.6 g/m2) and the 27-group (237.7 +/- 59.2 g/m2 to 146.7 +/- 20.6 g/m2) showed significant results. Freedom from event rates at seven years were 96.8 +/- 1.8% for thromboembolic events, 97.2 +/- 2.0% for thrombosed bioprosthesis, 96.6 +/- 2.6% for structural valve deterioration, 98.2% +/- 1.8% for nonstructural dysfunction, 95.9% +/- 2.0% for antithromboembolic hemorrhage, 98.9 +/- 1.1% for endocarditis and 93.9 +/- 3.2% for reoperation and explant (see Table 4). Early mortality (within 30 days) was 3.0%; late mortality was 4.6%/patient-year, including a valve-related mortality of 0.6%/patient-year. Of the patients, 96.5% showed an improvement of at least one NYHA class when comparing preoperative and one year status. DISCUSSION: The hemodynamic performance and the frequency of adverse events of the Mosaic bioprosthesis in the aortic position were very satisfactory within the first seven postoperative years with excellent results, comparable to studies about other established bioprostheses and similar to the findings in other Mosaic series. Only the number of cases of antithromboembolic hemorrhage was noticeably high. One reason might be the high percentage of patients under continuous anti-coagulant therapy: Six months postoperative, still 52.2% of the patients received phenprocoumon, 6.7% acetylsalicylic acid. Concerning hemodynamics, patient-prosthesis mismatch appeared to be a common problem, especially in small valve sizes. Separating the sample in groups with EOA index < or = 0.75 cm2/m2 and EOA index > 0.75 cm2/m2 after one year, 51.6% in the 21-group had an EOA index < or = 0.75 cm2/m2, whereas it was 19.4% (23), 18.8% (25) and 0% (27) in the larger size groups. Generally, further data have to be collected to determine durability of the biological tissue, as the critical period has just started with the seventh year of the clinical trial. CONCLUSION: The Mosaic bioprosthesis proved to be a reliable and well-functioning device for aortic valve replacement, especially in larger sizes.

End of the millenium--end of the single thoracic artery graft? Two thoracic arteries--standard for the next millenium? Early clinical results and analysis of risk factors in 1,487 patients with bilateral internal thoracic artery grafts.

PURPOSE: CABG with bilateral IMA grafts (BIMA) can improve long-term results in cardiac morbidity and mortality. An enhanced incidence of bleeding and wound complications compared to patients with single IMA (SIMA) remains a matter of debate. The aim of the study was to compare the operative outcomes of patients who had undergone CABG with BIMA and SIMA in situ grafts, especially to identify patient-related risk factors, such as obesity, diabetes mellitus and age above 70 years. METHODS: Out of a total of 5,144 patients operated on between January 1996 and September 1999, patients with isolated CABG (n = 3,671) with BIMA or SIMA were analyzed retrospectively. In the BIMA group, the patients' (n = 1,487) mean age was 64.0 years; mean EF was 62.1%. In the SIMA group (n = 2,184), the mean age was 65.4 years and mean EF 60.6% (n. s.). In the BIMA group, the right IMA was anterior of the aorta to the LAD, the left IMA to the lateral wall. In the SIMA group, the LAD was revascularisized with the left IMA. Additional bypasses were performed with vein grafts. RESULTS: The 30-day lethality was 1.6% in the BIMA group, 1.7% in the SIMA group in patients under 70, and 4.1% (BIMA) and 4.0% (SIMA) in patients over 70 (p = n.s.). A significantly higher blood loss was observed in the BIMA group (BIMA 979+/-708 ml, SIMA 790+/-575 ml, p<0.05). The rethoracotomy rate due to bleeding was significantly higher in patients with BIMA (4.1%) compared to those with SIMA (2.5%, p<0.05). In patients with a body mass index (BMI) of less than 27, no significant difference could be found (SIMA 2.8%, BIMA 3.4%, p = n. s.). Patients with a BMI >27 showed a significantly higher rethoracotomy rate (SIMA 2.2%, BIMA 4.9%). A higher incidence of sternal instabilities could be observed in the BIMA group (4.2%, p<0.05). Diabetes mellitus could not be identified as an independent risk factor for sternal complications (SIMA 2.9%, BIMA 5.0%, p = n. s.). COUCLUSION: CABG using both IMA's can be performed in nearly all patients as a routine method with good clinical results and low mortality. Bleeding in the BIMA group within 48 hours was increased. BMI >27 could be identified as a risk factor for sternal complications, but not diabetes mellitus or age over 70 years.

The Mosaic bioprosthesis in the aortic position at five years.

BACKGROUND AND AIM OF THE STUDY: The study aim was to collect intermediate-term data on the Mosaic bioprosthesis implanted in the aortic position. The device has been in clinical use since February 1994. METHODS: The Mosaic bioprosthesis is a stented porcine aortic valve, which combines a zero pressure differential fixation technique and anti-mineralization treatment with amino oleic acid for improved tissue durability. Between February 1994 and May 1999, 100 patients (49 females, 51 males; mean age at implant 73.4 +/- 7.3 years (range: 31-87 years) underwent aortic valve replacement with the Mosaic prosthesis in our department. Concomitant procedures were performed in 40% of cases. Patients were followed up prospectively at annual intervals; the mean follow up was 2.7 years (total 273.7 patient-years (pt-yr)) and was 100% complete. RESULTS: Total early mortality (within 30 days) was 3.0%; the late mortality rate was 4.4%/pt-yr and included a valve-related mortality rate of 0.7%/pt-yr. The freedom from event rates at five years were 97.3 +/- 1.9% for permanent neurological, 99.0 +/- 1.0% for transient neurological, 95.9 +/- 3.2 for thrombosed prosthesis, 95.6 +/- 2.2% for anti-thromboembolic-related hemorrhage, 100% for primary valvular leak, 96.9 +/- 3.0% for non-structural dysfunction, 100% for endocarditis, and 92.0 +/- 4.9% for explant. The mean systolic gradients were 15.2, 13.1 and 10.1 mmHg for the 21, 23 and 25 mm valve sizes, respectively. CONCLUSION: The clinical and hemodynamic performance of the Mosaic prosthesis was highly satisfactory during the first five years after clinical introduction. Further data will be necessary to confirm long-term durability.

[Mosaic bioprosthesis after 5 years]. / Mosaic-Bioprothese nach fünf Jahren.

The Mosaic bioprosthesis is a stented porcine aortic valve, which combines the zero pressure differential fixation technique (by applying equal pressure to the in- and outflow ends of the valve, the aortic root is pressurized to maximize the flow area while no pressure is exerted on the leaflets) and an antimineralization treatment with alpha amino oleic acid for improved tissue durability. The device is in clinical use since February 1994. The purpose of this study was to collect intermediate term data of the Mosaic bioprosthesis in the aortic position to evaluate its clinical and hemodynamic function. From February 1994 to May 1999, 100 patients underwent aortic valve replacement with the Mosaic prosthesis at our department. There were 49 female patients, mean age at implant was 73.4 +/- 7.3 years (range 31 to 87). Concomitant procedures were done in 40%. Preoperative and operative clinical data are shown in Tables 1 and 2. When assessing the size of the bioprosthesis, it is important to use the original Mosaic sizer. Because of the possibility of the so-called supra-x placement, the specific construction of the sizer and the Mosaic valve often allow the implantation of a 1-size larger valve compared to the conventional supra-annular placement. By this a significant increase in the effective flow orifice is possible. This proceeding is depicted in Figure 1. All patients have been anticoagulated with phenprocoumon at least for 3 months postoperatively, INR was aimed at 2.5 to 3.5. Patients have been followed up prospectively, within the initial hospitalization for valve replacement, 6 months postoperatively and at annual intervals including an hematological check and transthoracic echocardiography. The mean follow-up was 2.7 years with a total follow-up of 273.7 patient years. The follow-up was 100% complete. After 5 years the mean systolic pressure gradient was 15.2 +/- 3.0 mm Hg for the 21-mm, 13.1 +/- 4.6 mm Hg for the 23-mm, 10.0 +/- 3.1 mm Hg for the 25-mm valve size, the effective orifice area 1.6 +/- 0.3 cm2 (21-mm), 1.9 +/- 0.3 cm2 (23-mm) and 2.5 +/- 0.8 cm2 (25-mm) (see Table 3). The freedom from prosthesis-related event rates, calculated according to Kaplan-Meier, at 5 years were: 97.3 +/- 1.9% for permanent neurological, 99.0 +/- 1.0% for transient neurological, 95.9 +/- 3.2% for thrombosed prosthesis, 95.6 +/- 2.2% for antithromboembolic related hemorrhage, 96.2 +/- 3.7% for structural valve deterioration, 96.9 +/- 3.0% for non-structural dysfunction, 100% for endocarditis and 92.0 +/- 4.9% for explant (see Table 4). The total operative mortality (within 30 days) was 3.0%, the late postoperative mortality was 4.4% per patient year and included a valve related mortality rate of 0.7%/patient year. In Figure 2 the survival function after aortic valve replacement is depicted, arranged in freedom from all deaths, from Mosaic-related deaths and from Mosaic-related plus sudden/unexplained deaths. Before implantation of the Mosaic bioprosthesis 95% of the patients were in NYHA Classes III and IV, whereas 6 months postoperatively 98% could be classified in NYHA Classes I and II (see Figure 3). In relation to other biological prostheses (Intact, Carpentier-Edwards Pericardial and Porcine, Hancock Modified Orifice, Biocor, Freestyle) the Mosaic bioprosthesis showed very satisfactory and predominantly better hemodynamic results than the compared stented valves and approached the performance of stentless prostheses. The freedom rates from prosthetic-related adverse events of the Mosaic bioprosthesis were at least equivalent to the compared prostheses. However, the satisfactory freedom rates, especially from structural valve deterioration, should be qualified by considering the experience that most incidences appear from the 5th year on after implantation. The clinical and hemodynamic performance of the Mosaic prosthesis has been very satisfactory during the first 5 years after clinical introduction. Further data will be necessary to confirm long-term durability.