[Picture of the month. Staphylococcal infection with embolizations)].
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Adult↗
Biomedical subjects
L H Kristensen
Publications and source records attributed to L H Kristensen.
[Mortality and worsening of prognosis for patients with aortic stenosis while on the waiting list].
In a prospective study, 99 consecutive patients with an operative indication due to severe aortic stenosis (AS) were put on a surgical waiting list. The waiting time to aortic valve replacement (AVR) averaged 6.3 months (0.5-19 months). There were 58 men and 41 women with a mean age of 61 years (21-82 years). The patients were divided into three groups: group 1 (N = 81) with an uneventful stay on the waiting list; group 2 (N = 11) with significant worsening of a prognostic index; and group 3 (N = 7) with patients who died during the waiting time. The waiting list death rate was 13.5%/patient-year compared with a post-AVR death rate of 4.9% patient-year (p < 0.05) with a mean post-AVR follow-up of 5.7 years. According to a prognostic index (Cox regression model) at inclusion, group 2 patients had a predicted 7-year post-AVR survival probability of 72%, but only of 61% according to their prognostic index immediately preoperatively; their observed 7-year post-AVR survival was 60%. Logistic regression analysis identified high age, short duration of symptoms, signs of severe hypertrophy and strain in the ECG, female gender, and deranged left ventricular diastolic function (related to severely increased left ventricular muscle mass) as independent predictors of prognostic worsening and death while on the waiting list. The predictive models did not allow sufficiently accurate identification of the patients at risk during the waiting period. The consequences of a surgical waiting period averaging 6 months are serious for AS patients. The death rate is high and a subgroup worsens its prognostic profile with a significantly reduced post-AVR long-term survival as the result.
Adult↗
Myocardial structure as a determinant of pre- and postoperative ventricular function and long-term prognosis after valve replacement for aortic stenosis.
BACKGROUND: Long-term results after aortic value replacement for aortic stenosis can be correlated to a cardiac-related pre-operative risk profile. This predictability indicates that there is a common basis in subtle or overt structural abnormalities of left ventricular myocardium. METHODS AND RESULTS: Forty-nine patients aged 24-82 (mean 61) years, with aortic stenosis had a full wall thickness transmural biopsy of the left ventricular antero-lateral free wall during aortic valve replacement. Echocardiography and radionuclide ventriculography were performed prior to, and 18 months (n = 41) after, the operation. Postoperative follow-up to a maximum of 7.7 years was 100% complete. Pre-operatively, all patients had an increase in both the left ventricular mass index (202 +/- 67 g.m-2) and the muscle cell diameter (41 +/- 8 microns); other morphological data included a muscle cell nucleus volume of 752 +/- 192 microns3, a muscle cell mass index of 163 +/- 54.m-2, and a fibrous tissue mass index of 39 +/- 16 g.m-2. Patients with a pre-operative episode of clinical left ventricular failure (n = 19) had significantly greater morphological variables than those without. Pre-operative ejection fraction and other measures of systolic function correlated inversely with the morphological data, except for the fibrous tissue mass index; diastolic function indices correlated inversely with all the morphological variables. At the 18-month re-study, the same general picture was noted, but with an underlying strengthening, especially of the muscle cell mass index. Overall, the mass index dropped to 152 +/- 51 g.m-2 (P < 0.0001), but in 17% of the patients it became normal; the mass index at 18 months was directly correlated to morphological variables. A high muscle cell nucleus volume was identified as an independent predictor of early and late mortality. CONCLUSIONS: Abnormalities of the hypertrophied left ventricular muscle cell and the degree of muscle hypertrophy are, to some degree, underlying determinants of pre-operative symptomatology, pre- and postoperative ventricular function, and early and late mortality after valve replacement for aortic stenosis. Incomplete hypertrophy impaired results, was related to pre-operative myocardial structural abnormalities.
Adult↗
Impact of size mismatch and left ventricular function on performance of the St. Jude disc valve after aortic valve replacement.
BACKGROUND: The hemodynamic function of the St. Jude valve may change relative to changes in left ventricular function after aortic valve replacement for aortic stenosis. From theoretical reasons one may hypothesize that prosthetic valve hemodynamic function is related to left ventricular failure and mismatch between valve size and patient/ventricular chamber size. METHODS: Forty patients aged 24 to 82 years who survived aortic valve replacement for aortic stenosis with a standard St. Jude disc valve (mean size, 23.5 mm; range, 19 to 29 mm) were followed up prospectively with Doppler echocardiography and radionuclide left ventriculography preoperatively and 9 days, 3 months, and 18 months after the operation with assessment of intravascular hemolysis at 18 months. Follow-up to a maximum of 7.4 years (mean, 6.3 years) was 100% complete. RESULTS: Left ventricular muscle mass index decreased from 198 +/- 62 g.m-2 preoperatively to 153 +/- 53 g.m-2 at 18 months (p < 0.001), paralleled by a significant increase in left ventricular ejection fraction, peak ejection rate, and peak filling rate; only 18% of the patients had normal left ventricular muscle mass index and only 32% normal ventricular function (normal left ventricular ejection fraction, peak ejection rate, peak filling rate, early filling fraction, and late filling fraction during atrial contraction) at 18 months. Prosthetic valve peak Doppler gradient dropped from 20 +/- 6 mm Hg at 9 days to 17 +/- 5 mm Hg at 18 months (p < 0.05). Reduction of left ventricular muscle mass index was unrelated to peak gradient and size of the valve. Peak gradient at 18 months rose with valve orifice diameter of 17 mm or less (by 6 mm Hg), orifice diameter/body surface area of 9 mm.m-2 or less (by 5 mm Hg), left ventricular enddiastolic dimension (by 23 mm Hg per 10 mm increase), and impaired ventricular function (by 3 mm Hg). All but 2 patients (5%) had intravascular hemolysis; none had anemia. Two patients with moderate paravalvular leak had the highest serum lactic dehydrogenase levels; 4 patients with trivial leak had higher serum lactic dehydrogenase levels than those without leak. Serum lactic dehydrogenase levels rose with moderate paravalvular leak, impaired ventricular function, and valve orifice diameter. Six patients with trivial or moderate paravalvular leak had a cumulative 7-year freedom from bleeding and thromboembolism of 44% +/- 22% compared with 87% +/- 5% for those without leak (p < 0.05). CONCLUSIONS: The peak gradient of the St. Jude aortic valve dropped marginally over the first 18 postoperative months in association with incomplete left ventricular hypertrophy regression and marginal improvement of ventricular function. Mismatch between valve size and ventricular cavity size or patient size and impaired function of a dilated ventricle significantly compromised the performance of the St. Jude valve. Probably explained by platelet destruction or activation, paravalvular leak was related to bleeding and thromboembolic complications.
Adult↗
Left ventricular systolic and diastolic function in aortic stenosis. Prognostic value after valve replacement and underlying mechanisms.
AIMS: The aims of the study were to examine the prognostic value of pre-operative left ventricular systolic and diastolic function on early, and late mortality after valve replacement for aortic stenosis, and to identify possible underlying mechanisms. METHODS AND RESULTS: Ninety-one prospectively recruited consecutive patients with a mean age of 61 years underwent valve replacement for aortic stenosis with concomitant coronary artery bypass grafting in 32 and a minimum postoperative observation period of 5.4 years. There were six early (< or = 30 days postoperatively) and 19 late deaths, and 18 deaths from specific causes (cardiac and prosthetic valve related). Early mortality occurred exclusively among patients with a combined subnormal left ventricular systolic function (subnormal ejection fraction or peak ejection rate, or supranormal time-to-peak ejection--duration of systole ratio) and a subnormal fast filling fraction. In Cox regression models on crude mortality and specific deaths, a subnormal ejection fraction and a fast filling fraction of < or = 45% were the only independent risk factors. Patients with none of these risk factors had normal sex- and age-specific survival, those with any one factor had an early, and those with both factors a massive early and a late excess mortality, with 5-year crude survival of 92%, 77%, and 50%, respectively (P < 0.0001). Systolic wall stress was without prognostic value. Further analyses indicated that impairment of left ventricular function occurred with increasing muscle mass over two phases: (1) diastolic dysfunction characterized by a pattern of severe relative concentric hypertrophy; (2) the addition of systolic dysfunction characterized by a more dilated, less concentric chamber geometry. Coronary artery disease seemed to provoke the latter development sooner. CONCLUSIONS: Impaired systolic and diastolic left ventricular function, irrespective of afterload, were decisive independent pre-operative risk factors for early as well as late mortality after aortic valve replacement for aortic stenosis. The adverse influence of concentric hypertrophy was the main underlying mechanism. Operative intervention, before impairment of diastolic and systolic function, should be advocated.
Adult↗
Mortality and worsening of prognostic profile during waiting time for valve replacement in aortic stenosis.
In a prospective study 99 consecutive patients with operative indication due to severe aortic stenosis (AS) were put on a surgical waiting list. The waiting-time to aortic valve replacement (AVR) averaged 6.3 months (0.5-19 months). There were 58 men and 41 women with a mean age of 61 years (21-82 years). The patients were divided into three groups: group I (n = 81) with an uneventful stay on the waiting list (including one patient who declined the AVR offer); group II (n = 11) with significant worsening of a prognostic index; and group III (n = 7) with patients who died during the waiting-time. The waiting-list death rate was 13.5 +/- 5.0% patient-year-1 compared with a post-AVR death rate of 4.9 +/- 0.9%. patient-year-1 (p < 0.05) with a mean post-AVR follow-up of 5.7 years. According to their prognostic index at inclusion, group II patients had a predicted (by a Cox model) 7-year post-AVR survival probability of 72%, but only of 61% according to their prognostic index immediately preoperatively; their observed 7-year post-AVR survival was 60%. Logistic regression analysis identified high age, short duration of symptoms, severe hypertrophy and strain in the ECG, female sex, and deranged left-ventricular diastolic function (related to severely increased left-ventricular muscle mass) as independent predictors of death on the waiting-list and prognosis worsening. From a clinical viewpoint, the predictive models did not allow sufficiently accurate identification of the patients at risk during the waiting-time. The consequences of a surgical waiting-time averaging 6 months are serious for AS patients. The death rate is high and a subgroup worsen their prognostic profile, with significantly reduced post-AVR long-term survival as the result.
Aortic Valve↗
[Persistent symptoms after intake of hallucinogenic mushrooms].
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Adult↗
[Diagnosis of non-insulin-dependent diabetes in general practice].
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Aged↗
Complications by translumbar aortography.
The complications resulting from different methods of translumbar aortography were evaluated by checking 1192 examinations performed with 1) a cannula, 2) a straight catheter, and 3) a curved catheter. The latter method was found to be far more safe than the other two. According to the complication rates found in the literature the curved catheter translumbar method is also safer than the transaxillar and comparable to transfemoral aortography by the Seldinger method.
Aortography↗