Helmuth C. Mehmel

The effect of aortic valve replacement on survival.

We retrospectively studied 252 operated and 47 unoperated patients with isolated aortic valve disease. Aortic valve replacement (AVR) was recommended to all patients based on clinical and hemodynamic data. Preoperative hemodynamic and angiographic data were similar in operated and unoperated cohorts. Seventy-one percent of patients received a Bjork-Shiley prosthesis. Operative mortality was 7% for the entire surgical series. For patients with predominant aortic stenosis (AS), survival at 3 years was 87% in operated and 21% in unoperated patients (p < 0.001). For patients with predominant aortic insufficiency (Al), the 5-year survival rate was 86% in operated and 87% in unoperated patients (NS). AVR improved long-term survival inpatients with AS who had normal or impaired left ventricular (LV) function.In patients with Al and normal LV function, survival was not improved after AVR, but those with LV dysfunction who were operated on tended to survive longer (NS). Long-term survival of unoperated patients with AI was better than that in unoperated patients with AS. We conclude that AVR improves long-term survival in patients with AS who have normal or abnormal LV function, and that AVR does not change long-term survival in patients with Al, although those with LV dysfunction tended to survive longer.

The linearity of the end-systolic pressure-volume relationship in man and its sensitivity for assessment of left ventricular function.

The linearity and sensitivity of the end-systolic pressure-volume (P-Ves) relation to the inotropic state of the left ventricle were investigated in 11 patients with coronary heart disease and one patient with congestive cardiomyopathy. To minimize autonomic reflex responses, propranolol, 0.15 mg/kg, and atropine, 1 mg, were administered i.v. at the beginning of the study. Three ventriculograms were performed: at rest, after oral isosorbide dinitrate, 10 mg (systolic pressure decrease 15 ⩾ mm Hg), and during infusion of methoxamine, 2 mg/min (systolic pressure increase ⩾ 10 mm Hg).The three points of the P-Ves relation showed linearity (r ⩾ 0.96). The relation between the slope k of the PVes relation and the left ventricular ejection fraction at rest was best described by an exponential function (r = 0.94). The use of peak systolic pressure instead of end-systolic pressure showed equally good results. The intercept of the PVes line on the abscissa, which represents the theoretical end-systolic volume at zero pressure, was not related to the ejection fraction under control conditions. The P-Ves relation in postextrasystolic beats was displaced toward the left (smaller end-systolic volumes) and became steeper.

Ventricular arrhythmias in idiopathic dilated cardiomyopathy.

Twenty four hour ambulatory electrocardiograms were recorded in 60 patients with idiopathic dilated cardiomyopathy. The diagnosis was based on clinical, laboratory, and cardiac catheterisation findings. All patients had a left ventricular ejection fraction less than 0.55; in 39 it was less than 0.40. Ventricular extrasystoles were evident in all patients: they were rare in 11 (18%), moderately frequent in 24 (40%), and frequent in 25 (42%). Multiform extrasystoles were recorded in 57 patients (95%), paired ventricular extrasystoles in 47 (78%), and non-sustained ventricular tachycardias consisting of three to 19 beats in 25 (42%) of the 60 patients studied. Eight patients had more than five episodes of ventricular tachycardia a day. Patients with atrial fibrillation had the same frequency and grade of ventricular arrhythmias as those with sinus rhythm. Patients with infrequent and frequent ventricular extrasystoles could not be differentiated on the basis of the clinical or haemodynamic findings. The mean values of NYHA functional class, cardiac index, left ventricular end diastolic pressure, and ejection fraction were, however, significantly different in patients with and without ventricular tachycardia. During follow up of 12 +/- 5 months seven patients died; all seven had an ejection fraction less than 0.40. In four patients who died of congestive heart failure, but in only one of the three patients who died a sudden cardiac death, ventricular tachycardia was recorded during ambulatory monitoring. High grade ventricular arrhythmias are often seen in patients with idiopathic dilated cardiomyopathy; patients with ventricular tachycardia have more impairment of left ventricular function than patients without ventricular tachycardia; and ambulatory monitoring may be of little help in identifying patients at increased risk of sudden cardiac death.

Intracoronary thrombolysis in acute myocardial infarction: Duration of ischemia as a major determinant of late results after recanalization

To define the effect of duration of myocardial ischemia on the late results after successful thrombolysis in patients with acute transmural myocardial infarction, data on 39 patients treated with intracoronary infusion of streptokinase were analyzed. Patients with successful recanalization of infarct vessel and a time lag between onset of symptoms and reperfusion less than 4 hours were assembled in group A1 (n = 15), and patients with successful recanalization but a time lag of more than 4 hours (n = 17) in group A2. Group B consisted of 7 patients with unsuccessful thrombolysis. Coronary anatomy, left ventricular volume, ejection fraction, and regional ejection fraction of infarct area were determined before and 4 weeks after thrombolysis with cineangiography. Serum creatine kinase activity was serially measured. Before intervention, the groups were comparable with regard to age, Killip class, localization of infarction, incidence of previous infarction, Gensini score of coronary anatomy, left ventricular volume, ejection fraction, regional ejection fraction of infarct area, and serum creatine kinase activity. Four weeks after the intervention, patients in group A1 had a higher ejection fraction (59%) and regional ejection fraction of infarct area (39%) than patients in group A2 (ejection fraction: 49%, p less than 0.05; regional ejection fraction: 26%, p less than 0.05) and group B (ejection fraction: 44%, p less than 0.05; regional ejection fraction: 25%, p = 0.05). Peak serum creatine kinase activity measured during the acute illness was lower in group A1 (764 U/liter) than in group A2 (1,580 U/liter, p less than 0.05) and group B (2,106 U/liter, p less than 0.05). Thus, contraction of infarct area was improved and enzymatic estimate of infarct size was reduced after early as compared with late reperfusion in patients with acute myocardial infarction.

Thrombolysis in acute myocardial infarction using intracoronary streptokinase: assessment by thallium-201 scintigraphy.

Twenty-one patients with acute myocardial infarction, admitted to the hospital within 4 hours after the onset of symptoms, were studied by seven-pinhole thallium-201 scintigraphy before and I hour and 24 hours after intracoronary fibrinolysis using streptokinase. The size of the thallium-201 perfusion defect was assessed from myocardial cross sections reconstructed from the original seven-pinhole data and expressed as a fraction of left ventricular circumference.Recanalization was achieved in 16 patients within 3.9 ± 1.6 hours after onset of symptoms (group A). In these patients, the size of the perfusion defect had decreased from 36 ± 17% to 19 ± 15% (p < 0.001) at 24 hours. No significant change was detected by redistribution at 1 hour after the intervention. In five patients, intracoronary fibrinolysis was unsuccessful, and the vessel remained occluded (group B). The thallium-201 perfusion defect affected 40 ± 15% of the left ventricular circumference before the intervention; it remained virtually unchanged at 1 hour (37 ± 16%) and at 24 hours (41 ± 15%) after fibrinolysis. The perfusion defect was most reduced in patients with extensive collaterals supplying the ischemic area or with subtotal occlusion of the affected coronary artery.We conclude that successful intracoronary fibrinolysis may reduce the size of the thallium-201 perfusion defect in many patients with acute myocardial infarction. One important factor in the final result may be the presence of residual coronary flow supplied by extensive collaterals or by subtotal occlusion of the affected coronary artery when reperfusion is achieved around 4 hours after the onset of symptoms.

High-fidelity left ventricular pressure measurements for the assessment of cardiac contractility in man

Abstract Left ventricular contractility was assessed in 110 patients by use of Vmax values derived from high-fidelity left ventricular pressure measurements. Instantaneous velocity of shortening of the contractile elements (V CE ) throughout the isovolumic phase of left ventricular systole was calculated by an analog computer using the formula: V CE in muscle lengths (ML)/ sec = ( dP / dt )/28 · P where P represents total left ventricular pressure and dP/dt its first derivative. Vmax was obtained by manual straight line extrapolation of the descending portion of the pressure-velocity curves. Group 1 (control subjects) consisted of 25 patients with no or minimal loading of the left ventricle. Vmax in Group 1 was 1.86 ML/sec. Group 2 consisted of 25 patients with atrial septal defect and Group 3 included 11 patients with slight left ventricular pressure load. In Groups 2 and 3, the Vmax value was not significantly different from that of Group 1. However, in Group 4, which consisted of 23 patients with moderate to severe left ventricular pressure load, Vmax was significantly reduced (1.53 ML/sec); in Group 5, which consisted of 14 patients with coronary artery disease and 6 patients with cardiomyopathy, Vmax was 1.21 ML/sec; and in Group 6, comprising 6 patients with mitral stenosis, Vmax was 1.26 ML/sec. In individual patients in Groups 3 to 5, assessment of contractility by comparison with resting Vmax values was not always satisfactory because of overlap with the range of the control subjects. Isometric exercise by handgrip carried out in 44 patients allowed further differentiation of individual contractile function. In Groups 1 and 2, the response to handgrip was characterized by a significant increase of Vmax with no alterations or changes not exceeding +4 mm Hg of left ventricular end-diastolic pressure. In Groups 3 to 5, we observed normal responses, as well as abnormal reaction to handgrip (increase of Vmax associated with an increase of left ventricular end-diastolic pressure that exceeded 4 mm Hg) and pathologic reaction to handgrip (decrease of Vmax accompanied by an increase of left ventricular end-diastolic pressure). Seven of 13 patients with a normal resting Vmax showed an abnormal or a pathologic reaction. A normal response to handgrip was observed in a few patients with depressed resting Vmax. It is concluded that identification of individual patients with impaired myocardial contractile function requires determination of Vmax both at rest and during an additional stress such as isometric exercise.

Effect of Successful Thrombolytic Therapy on Right Ventricular Function in Acute Inferior Wall Myocardial Infarction

In 19 patients undergoing intracoronary fibrinolytic therapy for acute myocardial infarction, the site of coronary obstruction was in the proximal right coronary artery. Time between onset of symptoms and hospitalization was less than 4 hours. These patients were studied prospectively by radionuclide techniques immediately after admission, 48 hours and 4 weeks after AMI. Right and left ventricular (RV and LV) ejection fractions (EF) were calculated from gated blood pool scintigrams and the size of the LV perfusion defect was assessed by thallium-201 scintigraphy. Before the intervention, RV performance was significantly lower (RVEF 29 +/- 8%) than normal (53 +/- 7%). The size of the LV perfusion defect was relatively small (less than 25% of LV circumference), and as a consequence, LV pump function was only marginally impaired (LVEF 54 +/- 11%). Recanalization of the infarct artery was achieved in 12 patients (group A); in 7 patients the infarct artery remained occluded (group B). Early after the intervention (48 hours), RV performance in group A recovered significantly (RVEF: 30 +/- 9% vs 39 +/- 7%, p less than 0.01), and further improvement was noted at 4 weeks (RVEF 43 +/- 5%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive assessment of myocardial contractility in asymptomatic patients with severe aortic regurgitation and normal left ventricular ejection fraction at rest

In 14 asymptomatic patients with isolated aortic insufficiency the slope k of the end-systolic pressure-volume relation was determined noninvasively with equilibrium radionuclide angiography. The results were compared with changes in left ventricular ejection fraction during maximal physical stress. Nine normal volunteers served as a control group. Patients with aortic insufficiency did not differ significantly from the control group with respect to left ventricular ejection fraction at rest (aortic insufficiency 62 + 8 percent, control 65 +/- 6; probability [p] = not significant [NS]), physical work capacity (aortic insufficiency 113 +/- 32 watts, control 117 +/- 25; p = NS) or age (aortic insufficiency 40 +/- 10 years, control 47 +/- 7; p = NS). The slope (k) of the end-systolic pressure-volume relation was found to be significantly lower in the group with aortic insufficiency (3.1 +/- 1.1) than in the control group (4.1 +/- 0.5; p less than 0.05). Patients with aortic insufficiency could be classified into two subgroups with respect to the slope k. In subgroup A (n = 7) the slope fell within the normal range (4.0 +/- 0.6) as defined by the control group, and the left ventricular exercise reserve was normal (6 percent +/- 1). In subgroup B (n = 7) the slope was significantly lower (2.2 +/- 0.6, p less than 0.01), indicating depressed myocardial contractility, and all patients experienced left ventricular dysfunction during exercise (left ventricular exercise reserve -5 +/- 5 percent). Thus, noninvasive determination of the end-systolic pressure-volume relation identified two subsets of asymptomatic patients with aortic insufficiency, one with impaired myocardial contractility and normal left ventricular exercise reserve and a second group with depressed myocardial contractility and left ventricular dysfunction during exercise. Therefore, an abnormal baseline contractile state in asymptomatic patients with aortic insufficiency may be uncovered by noninvasive determination of the end-systolic pressure-volume relation or by assessing the left ventricular exercise reserve. Serial studies in a larger group of patients undergoing surgical correction of the valve lesion are indicated to determine whether this information will be helpful in evaluating when to operate on asymptomatic patients with aortic insufficiency.

Incidence, management, and outcome of stent loss during intracoronary stenting.

C stent embolization is an uncommon but potentially hazardous complication of percutaneous transluminal coronary angioplasty (PTCA). Previous small-sized clinical studies reported incidence rates ranging from 0.9% to 8.4%.1–5 In this study we report the incidence, management, and hospital follow-up of a large, consecutive series of patients with coronary stent embolization. • • • The German registry of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausarzte includes prospectively all PTCA procedures from 74 centers since October 1992. The organization of the registry has been published elsewhere.6 Two audit visits per year ensured the completeness of the data including complications. From August 23, 1995, to June 28, 1997, a total of 56,807 PTCA procedures were registered. In 20,298 patients,

Ventricular arrhythmias before and late after aortic valve replacement

1 stents were implanted (implantation rate 35.7%). A total of 25,558 stent implantations resulted in 1.26 stents per procedure. Four hundred twenty-nine lost stents were documented and were analyzed retrospectively by a detailed questionnaire. The clinical follow-up on 18 patients was incomplete or not available. Thus, the study presents data of 411 stent embolizations in 387 patients involving 96% of all stents lost (Table 1). During the same time interval, similar data from 19,869 consecutive patients having undergone stent procedures without embolization were collected; these patients served as a control population to the lost stent cohort. The outcomes of interest were all-cause mortality, nonfatal acute myocardial infarction (AMI), the need for coronary artery bypass graft (CABG) surgery, and noncoronary sequelae after stent embolization. Continuous variables are expressed as mean 6 1 SD. The likelihood ratio test as chi-square test was used to test homogeneity; the significance was calculated by Fisher’s exact test. A 2-tailed p value ,0.05 was considered significant. Baseline characteristics of patients who had stent embolization are detailed in Table 1. On the basis of 25,558 implanted stents and 20,298 treated patients the incidence of stent loss amounted to 1.7% per implanted stent and 2.1% per treated patient. Patients with stent loss were older than patients without stent loss (64.4 6 9.2 vs 60.7 6 9.7 years; p ,0.001). Angiographic characteristics, target lesions, and technical approach are listed in Table 2. A multiple group comparison identified 3 groups of target lesions: stent embolization in the left anterior descending coronary artery was underrepresented, whereas embolization in the left main coronary artery was overrepresented. Stents placed in the left circumflex artery, right coronary artery, and bypass graft showed average rates of embolization (p ,0.0001). The number and type of lost stents are detailed in Table 3. For statistical purposes only, stent types with .1,000 implantations were considered. The 4 major stent types, Palmaz-Schatz, Micro-stent, MultiLink, and Wiktor (68.1% of implantations) were composed of 6.9% of lost stents. However, 3 groups of stent embolization rates could be distinguished. Manually crimped Palmaz-Schatz and Wiktor stent embolized most often, whereas the MultiLink stent embolized least. The Micro, Pura, Nir, and Sitomed stent showed average rates of stent embolization (p ,0.001). The causes of stent loss, their location, and management are presented in Table 4. The operator tried to retrieve the embolized stent in 63% of cases. However, only 118 stents (29%) could be retrieved. In 36 cases (9%) the guiding catheter sprung uncontrollably into the aortic root during catheter manipulations pulling the stent-balloon assembly together with the guidewire outside the coronary artery. In 4 cases an inserted stent was displaced when it was crossed by a second stent. In another 4 cases a second stent embolized while crossing an already deployed stent. Only 1 embolization was due to balloon rupture. The stent was lost within the coronary arteries in 45% of cases and outside the coronary arteries in the remainder. Eighty-two embolized stents were successfully implanted or fixed in a site initially not selected From the General Hospital Hamburg-Altona; Klinikum Ingolstadt; Klinikum Kassel; Zentral-Krankenhaus Links der Weser Bremen; and Stadtische Kliniken Karlsruhe, Hamburg, Germany. Dr. von Olshausen’s address is: 3rd Medical Department, Cardiology, General Hospital Hamburg-Altona, Paul-Ehrlich-Strasse 1, D-22763 Hamburg, Germany. E-mail: klausvo@t-online.de. Manuscript received November 24, 2000; revised manuscript received and accepted April 11, 2001. TABLE 1 Characteristics of 387 Patients With Stent Loss