Bircks W

Lower intensity anticoagulation therapy results in lower complication rates with the St. Jude Medical prosthesis

Six hundred consecutive patients were operated on between September 1978 and October 1982 for isolated aortic (n = 298), mitral (n = 215), or multiple valve replacement (n = 87) with the St. Jude Medical bileaflet prosthesis. Mean age of the 303 female and 297 male patients was 50.7 +/- 9.6 (range 12 to 83) years. All patients were followed up prospectively; follow-up was complete and averaged 122.2 +/- 1.1 months for operative survivors. Total follow-up for aortic patients was 2904.1 patient-years, for mitral replacement 1859.5 patient-years, and for multiple valve replacement 736 patient-years. When the prothrombin times measured with different thromboplastins were converted into an international normalized ratio, four patient groups could be separated; that is, the groups comprised patients whose anticoagulation was maintained during the follow-up within an international normalized ratio corridor of 4.0 to 6.0, 3.0 to 4.5, 2.5 to 3.5, or 1.75 to 2.75. Less intensive anticoagulation in terms of the international normalized ratio values caused only a mild increase in the incidence of thromboembolic complications but a highly significant decrease in the rate of bleeding. Severe bleeding complications in the aortic valve group were highest with an international normalized ratio of 4.0 to 6.0 (1.15 per patient-year) and lowest with an international normalized ratio of 1.75 to 2.75 (0.24 per patient-year). The same held true for patients with single St. Jude Medical mitral valve replacement (2.09 per patient-year versus 0.72 per patient-year) and multiple valve replacements (4.45 per patient-year versus 1.20 per patient-year). These results suggest that the generally recommended international normalized ratio of 3.0 to 4.5 may be too high for patients with St. Jude Medical aortic valve replacement and also for patients with St. Jude Medical prostheses in the mitral position if, with respect to the thromboembolic hazard, there is not a predominating patient-related comorbidity. A large multicenter prospective randomized study is therefore proposed to establish the safe international normalized ratio levels accompanied by the lowest complication rates for both bleeding and thromboembolic events after St. Jude Medical prosthesis implantation (German experience with low intensity anticoagulation study).

Techniques and complications of transaortic subvalvular myectomy in patients with hypertrophic obstructive cardiomyopathy (HOCM)

The natural history of hypertrophic obstructive cardiomyopathy (HOCM) is usually characterized by development of mitral insufficiency, congestive heart failure (CHF) and sudden death. In patients (pts) belonging to at least clinical class III (NYHA) after failed medical therapy (beta-blocking agents and calcium-antagonists) surgery should be considered (by means of transaortic subvalvular myectomy). The history and development of different surgical techniques and procedures has been described in detail since 1958, when Cleland performed the first transaortic subvalvular myotomy. Our surgical series (1963-May 31, 1986) consists of 212 pts (mean age 40 years, range 6-73 years) with typical and atypical HOCM. The total hospital mortality rate was 6.6% (n = 14), which was reduced to 3.8% (n = 6), if only transaortic subvalvular myectomy (TSM) was performed (n = 160). In the group of 52 pts with additional surgical procedures the mortality rate was 15.4% (n = 8). The main problems occurred in pts with additional mitral valve replacement (MVR) (n = 15, three deaths). The rate of HOCM-related complications (secondary VSD, total AV-block, cerebral embolism, intraoperative re-myectomy) and those related to surgery (bleeding, pulmonary embolism, wound dehiscence, septicemia) was low. Therefore TSM for HOCM is a low-risk surgical procedure with a good long-term prognosis. However, in pts with a need for additional surgical procedures, the risk is considerably increased. Subjective impression of the pts and hemodynamic data indicate a clear clinical improvement postoperatively. Concerning long-term survival and reduction of the sudden death rate, our data do not allow a final judgement at the moment.

Prediction of the site and severity of obstruction in hypertrophic cardiomyopathy by color flow mapping and continuous wave Doppler echocardiography

OBJECTIVE We investigated whether the site and severity of an obstruction in hypertrophic cardiomyopathy can be accurately predicted by the combined use of color-coded and continuous wave Doppler echocardiography. BACKGROUND Predicting the site of obstruction by end-systolic cavity shape is not reliable. Therefore, hemodynamic localization of the obstruction is required before surgery is performed. Such localization should be possible with color flow imaging, which provides two-dimensional velocity mapping reflecting the distribution of pressures within the left ventricle. Discrepancies in assessment of the pressure gradient by Doppler echocardiography and cardiac catheterization (which are usually not performed simultaneously) may be due to spontaneous variation of the dynamic obstruction in addition to technical factors related to both methods. METHODS Twenty consecutive patients with hypertrophic cardiomyopathy were examined 1 day before transseptal left heart catheterization. The obstruction site was defined by color flow mapping. The pressure gradient was determined by continuous wave Doppler echocardiography. Measurements were also performed simultaneously in 10 patients during cardiac catheterization. RESULTS Midventricular obstruction was correctly identified in 4 patients and subvalvular obstruction in 15 patients. One patient had no obstruction at rest. Invasively and noninvasively determined pressure gradients correlated well (r = 0.89, SEE = 16.3 mm Hg). Multiple single-beat analysis in 10 patients, also simultaneously examined with Doppler echocardiography and catheterization, yielded an excellent correlation (r = 0.97, SEE = 13.1 mm Hg). Comparing the simultaneous (r = 0.96, SEE = 12.5 mm Hg) and nonsimultaneous (r = 0.81, SEE = 23.8 mm Hg) recordings in these patients, we found that the spontaneous variation of the dynamic obstruction mainly accounted for discrepancies (p less than 0.05). CONCLUSION The combined use of color-coded and continuous wave Doppler echocardiography provides the relevant hemodynamic information required for decision-making in patients with hypertrophic cardiomyopathy who are considered for transaortic myectomy.

Cardiac rhythm after Mustard repair and after arterial switch operation for complete transposition

We compared the prevalence of arrhythmias among the first consecutive 45 patients with complete transposition (concordant atrioventricular and discordant ventriculo-arterial connexions) after arterial switch operation and the last 47 patients after Mustard repair in infancy. Both groups had 24-hour Holter electrocardiographic studies at similar periods of follow up (24 +/- 14 and 25 +/- 18 months). A second group of patients undergoing the Mustard procedure had been repaired at an older age before 1981. They were studied to determine the frequency of disturbances of rhythm during later postoperative follow-up (85 +/- 24 months). Symptomatic brady-/tachyarrhythmia syndrome never occurred after the arterial switch and only once in the group of patients repaired by the Mustard procedure in infancy, but developed at a late stage (69 +/- 28 months); five times in the group of patients having Mustards repair at an older age. In addition, Holter monitoring did not detect bradyarrhythmias indicating sinus node dysfunction in a single patient after the arterial switch, but did so to a similar extent in both groups having the Mustard procedure (recent: n = 14; older: n = 18). Three cases of the group of older patients undergoing a Mustard operation developed complete atrioventricular block during follow-up. Normal findings were present in 93% of the cases after arterial switch, but in only 51% of the cases with a similar follow-up repaired by the Mustard procedure, and in 29% of the group having the Mustard repair at an older age.(ABSTRACT TRUNCATED AT 250 WORDS)

Duplex sonography of the internal thoracic artery: Preoperative assessment

Ultrasonic duplex scanning was used to examine 211 internal thoracic arteries. The investigating vessels were classified as normal, abnormal, and occluded. The results of the duplex examination were compared with angiography as the reference method. The diameter measurements showed virtually no differences between the two methods. Normal internal thoracic arteries showed a continuous decrease of the systolic flow velocities from proximal to distal and a narrow to moderate spectral flow curve, whereas arteries classified as abnormal showed a velocity profile distinct from that--in particular, no decrease of the systolic peak velocities and an increased spectral broadening during systole with peak frequencies greater than 4 kHz at 60 degrees (> 1.2 m/sec). In occluded vessels no flow could be detected. The majority of changes were found in the proximal part of the internal thoracic artery. All lesions were detected by duplex sonography. Six normal vessels were misjudged as abnormal by the duplex method. The sensitivity, specificity, and accuracy of duplex sonography compared with angiography as the reference method were 100% (95% CI, 74.4% to 100%), 96.9% (95% CI, 93.2% to 98.8%), and 97.2% (95% CI, 93.6% to 98.8%), respectively. Duplex sonography is a reliable, noninvasive technique for the preoperative assessment of the internal thoracic artery. It allows the detection of potential atherosclerotic changes in the internal thoracic artery and the assessment of adequacy of caliber and flow.

Predictable correction of tricuspid insufficiency by semicircular annuloplasty.

During surgical correction of multivalvular lesions, acquired tricuspid insufficiency is best treated by a semicircular annuloplasty technique. In order to achieve an individualized and accurate correction, the tricuspid annuloplasty suture is tied around an obturator, the dimensions of which are based upon Carpentiers tricuspid ring.

Mitral Valve Replacement Using Different Prosthetic Valves

6 ,, I I 5 ,, ,, 4 , + 3 •,,, 2 •I, 21 Fig. 2 Diastolic pressure gradients in patients with mitral valve prostheses of equal tissue annulus diameters. The comparison is limited by the small number of patients in the Hail-Kaster group. hemodynamics and thrombogenicity is expected as a result of its central flow pattern and the total pyrolytic carbon construction (3). 40 patients with Bjork-Shiley, 22 pts. with St. Jude Medical and 6 pts. with Hall-Kaster valves were restudied one year after operation (Fig. 1). The preoperative data were not different in these 3 groups. About 65% of the pts. had had predominant mitral stenosis. More than 70% had been classified as class III (NYHAj, the others as class IV. Mitral valves Prosthetic valves Cardiac surgery

Results of randomized mitral valve replacement with mechanical prostheses after 15 years.

Between 1974 and 1976 150 consecutive patients (pts) were operated on for isolated mitral valve replacement (MVR). Björk-Shiley (BS), Lillehei-Kaste (LK), and Starr-Edwards (SE) (type 6210) prostheses were implanted at random. All survivors were prospectively followed by regular clinical examinations every 6 to 12 months for 15 years. The mean follow-up time was 14.8 years. A constant subjective improvement after 15 years was reported in 62% of pts with BS, 30% with LK, and 49% with SE. The cumulative 14-year survival rate was 0.62 ± 0.13 (BS), 0.56 ± 0.16 (SE), and 0.54 ± 0.15 (LK), respectively. Late mortality was due to thromboembolic events (n=3), bleeding complications (n=3), congestive heart failure (n=7), documented arrhythmias or sudden death (n=6). Thrombotic valve thrombosis (1 BS, 1 LK, 2 SE) required reoperations. Linearized cumulative rates after 14 years for thromboembolic complications were 14.2 ± 3.1 (BS), 15.8 ± 3.7 (SE), 24.3 ± 4.2 (LK). The cumulative risk of severe bleeding complications was not different: BS: 35.8, LK: 35.2, SE: 34.3. During the first years of observation no significant differences between these mechanical prostheses could be observed, however, after 14 years of long-term follow-up the cumulative event-free rates were more favorable for the BS prosthesis.

Is the Late Outcome of Heart Valve Replacement Influenced by the Hemodynamics of the Heart Valve Substitute

Although many of the problems of the early years of heart valve replacement seem to be solved, other problems still remain. For example, the high operative mortality of the early years has decreased to less than 5% (1); today operative long-term complications (2) and insufficient recovery from preoperative myocardial dysfunction (3) are of much more concern.

Quality of life and prognosis following heart valve replacement

Heart valve replacement, after more than three decades of continuous efforts to improve the prostheses, has become a routine procedure. Apart from some recent set-backs with a mono-tilting disc [1] and one bi-leaflet prosthesis [2], the mechanical prostheses used today are reliable and durable for the period for which they have been followed and likely for a much longer time. Thrombogenicity, the major disadvantage of all mechanical heart valve prostheses, has also been reduced by designs allowing a more physiological transprosthetic flow profile and by use of the more biocompatible pyrolytic carbon [3–5].