Severe Aortic Valvular Disease Research Articles

Multimodality Assessment of Ascending Aortic Diameters: Comparison of Different Measurement Methods

Transthoracic echocardiography (TTE), multidetector computed tomography (MDCT), and magnetic resonance imaging (MRI) have been widely used to monitor aortic diameters, with no consensus as to the best measurement approach. Thus, the aim of this study was to establish the best measurement methods by two-dimensional (2D) TTE, MDCT, and MRI to achieve comparable aortic diameters. One hundred forty patients with severe aortic valvular disease or aortic dilatation were prospectively evaluated using 2D TTE and MDCT (n=70) or MRI (n=70). The aorta was measured at three different levels: sinuses of Valsalva, sinotubular junction, and ascending aorta. Three different measurements were made by 2D TTE-inner edge to inner edge, leading edge to leading edge (L-L), and outer edge to outer edge-and then compared with the inner edge-to-inner edge and outer edge-to-outer edge measurements of cusp-to-cusp and cusp-to-commissure diameters by MDCT or MRI. Inter- and intraobserver variability was analyzed. Aortic diameters by 2D TTE, MDCT, and MRI showed excellent inter- and intraobserver variability usingall conventions. Significant underestimation was observed of all aortic diameters assessed by 2D TTEusing the inner edge-to-inner edge convention compared with those obtained by MDCT or MRI (P<.0001). However, excellent accuracy was observed by 2D TTE when the L-L convention was used and compared with the internal diameter by MDCT and MRI (mean differences, 0.6±2.6mm [P=.158] for MDCT and 0.4±3.5mm [P=.852] for MRI). Cusp-to-cusp diameters were slightly larger than cusp-to-commissure diameters. The diameter by 2D TTE using the L-L convention correlated best with the noncoronary cusp-to-right coronary cusp diameter determined by both MDCT and MRI. Aortic root and ascending aortic diameters measured by 2D TTE using the L-L convention showed accurate and reproducible values compared with internal diameters assessed by MDCT or MRI. This approach permits a multimodality follow-up of patients with aortic diseases and avoids disparities in measurementsobtained by different conventions.

Antithrombotic treatment in patients undergoing transcatheter aortic valve implantation (TAVI).

Transcatheter aortic valve implantation (TAVI) is an established treatment option for symptomatic patients with severe aortic valvular disease who are not suitable for conventional surgical aortic valve replacement. Despite improving experience and techniques, ischaemic and bleeding complications after TAVI remain prevalent and impair survival in this generally old and comorbid-rich population. Due to changing aetiology of complications over time, antiplatelet and anticoagulant therapy after TAVI should be carefully balanced. Empirically, a dual antiplatelet strategy is generally used after TAVI for patients without an indication for oral anticoagulation (OAC; e. g. atrial fibrillation, mechanical mitral valve prosthesis), including aspirin and a thienopyridine. For patients on OAC, a combination of OAC and aspirin or thienopyridine is generally used. This review shows that current registries are unfit to directly compare antithrombotic regimens. Small exploring studies suggest that additional clopidogrel after TAVI only affects bleeding and not ischemic complications. However, these studies are lack in quality in terms of Cochrane criteria. Currently, three randomised controlled trials are recruiting to gather more knowledge about the effects of clopidogrel after TAVI.

Effective Anticoagulation for a Percutaneous Ventricular Assist Device Using a Heparin-Based Purge Solution

To report on a series of patients who were successfully anticoagulated with a novel protocol including a heparin-based purge solution. Four patients were supported for a total of 300 hours on the new Impella anticoagulation protocol, which was based on our current nurse-driven cardiology heparin protocol. Three patients were in cardiogenic shock after acute myocardial infarction, and 1 patient was in shock from severe aortic valvular disease. Despite prolonged cardiogenic shock, none of the patients developed significant renal or liver dysfunction while on device support. All 4 patients survived to hospital discharge, and there were no significant bleeding or thromboembolic events. Furthermore, there were no device malfunctions or clotting events within with pump motors. Despite frequent changes to the purge solution flow rate by the Automated Impella Controller, the patients in our cohort had relatively stable activated partial thromboplastin time values. Our novel anticoagulation protocol, which incorporates the heparin included in the purge solution into the total hourly heparin dosage, was successful in the first cohort of patients receiving extended Impella support for cardiogenic shock. Our case series also highlights that the Automated Impella Controller makes frequent adjustments to the purge solution, which depending on the heparin concentration, can result in significant fluctuations in the patient's total hourly heparin dosage. Furthermore, balancing the heparin in the purge solution with the intravenous heparin is important to ensuring adequate anticoagulation in patients supported by the Impella devices in the intensive care unit. Development of a standardized anticoagulation protocol for the Impella device that factors the heparin-based purge into the total heparin dosage and makes appropriate adjustments based on the fluctuating rate of the purge solution can provide effective anticoagulation to patients receiving extended circulatory support from this device.

Experience with emergency cardiac surgery following institution of percutaneous cardiopulmonary support.

Between August 1992 and February 1998, 43 patients were treated with percutaneous cardiopulmonary support (PCPS) in our institution, and 8 of them subsequently required emergency cardiac surgery. There were 3 males and 5 females with a mean age of 63 years (range, 37 to 81 years). The etiology of shock in these 8 patients was acute myocardial infarction in 3, postinfarction left ventricular (LV) free wall rupture in 1, postinfarction ventricular septal perforation (VSP) in 1, LV free wall rupture and VSP in 1, and fatal arrhythmia due to severe aortic valvular disease in 2. The mean time interval from the onset of cardiogenic shock to the institution of PCPS was 77 min (range, 18 to 183 min). The mean time interval from the institution of PCPS until surgery was 145 min (range, 40 to 603 min). The surgical procedures were coronary artery bypass grafting (CABG) in 3 patients, closure of the LV rupture and/or closure of VSP in 3, and aortic valve replacement in 2. Six patients were weaned from PCPS, and 2 patients were discharged from the hospital (discharge rate, 25%). Although the results of emergency cardiac surgery following PCPS still are not satisfactory, we continue to apply PCPS and perform appropriate surgical procedures to improve the survival rate of the patients who would die without PCPS.

Gender-Associated Differences in Left Ventricular Geometry in Patients With Aortic Valve Disease and Effect of Distinct Overload Subsets

Gender-associated differences may play an important role in the way the left ventricle adapts to overload. The purpose of this study is to evaluate left ventricular (LV) geometry in patients referred for aortic valve replacement with distinct overload subsets. The echocardiograms of 128 patients with isolated aortic stenosis (n = 44), mixed aortic valvular disease (n = 51), and pure aortic regurgitation (n = 33) before aortic valve replacement were evaluated. Women had better LV function as measured by ejection fraction (58% vs 52%; p = 0.01) and were slightly older (67 vs 62 years, p = 0.11). LV dimensions and volumes indexes were distinctively smaller in women irrespective of the subgroups analyzed. Men had larger LV mass and LV mass index, but women had higher LV mass/volume ratio. Gender-related differences in LV mass/volume ratio were most prominent in the aortic stenosis patients (3.1 g/ml for women vs 2.3 g/ml for men; p = 0.001), tended to decrease in mixed aortic disease (2.3 g/ml for women vs 1.8 g/ml for men; p = 0.01), and were not present in patients with pure aortic regurgitation (1.7 g/ml for women vs 1.7 g/ml for men; p = 0.83). Multivariate analysis showed that gender was independently associated with LV mass/volume ratios, after adjusting for the severity of the valvular lesion, age, LV function, and concomitant coronary bypass graft surgery. Thus, in a selected population of patients with severe aortic valvular disease, there were significant gender-related differences in LV geometry, mainly in patients exposed to chronic pressure overload.

Aortic valve replacement and splenectomy in a patient with chronic idiopathic thrombocytopenic purpura—preoperative management with high-dose γ-globulin

We report the management of a patient with chronic idiopathic thrombocytopenic purpura and severe aortic valvular disease. Preoperative intravenous high-dose gamma-globulin administration was employed, and aortic valve replacement combined with splenectomy were performed during the same operation. The platelet count at admission was 34,000/mm3 and increased to 146,000/mm3 after the gamma-globulin therapy. Platelet transfusion at the end of the cardiopulmonary bypass was considered no longer necessary in the postoperative period, because the platelet count increased quickly after the procedure. The postoperative course was uneventful. We believe that open heart surgery and splenectomy can successfully be performed simultaneously in a patient with chronic idiopathic thrombocytopenic purpura treated with high-dose gamma-globulin therapy.

Total and Split Renal Function Assessed by Ultrasound Doppler Techniques

We evaluated total and split renal functions from the pattern for renal arterial blood flow detected by ultrasound Doppler in healthy subjects and patients with varying degrees of renal function and disorders other than renovascular hypertension or severe aortic valvular disease. A renal-time pulsed ultrasonic echo-Doppler device at 2.5 MHz was used with a translumbar approach. The ratio of peak diastolic (D) to systolic (S) velocity correlated well with both p-aminohippurate clearance and creatinine clearance. Acceleration time was correlated with the clearance of neither compound. To evaluate the clinical usefulness of ultrasound Doppler in the assessment of split renal function, we compared the D/S ratio with the renal function obtained by radionuclide methods for individuals. The split renal glomerular filtration rate, calculated by a method which makes use of the early renal uptake of 99mTc-diethylenetriam-inepentaacetic acid, correlated well with the D/S ratio. These results indicate that the ultrasonic measurement of renal arterial blood flow by the pulsed Doppler method should be useful for assessment of total and split renal functions.

緊急手術を要した重症大動脈弁膜症

緊急手術を要した重症大動脈弁膜症

Clinical experience with enlargement of the aortic anulus by extension of the aortic incision into the anterior mitral leaflet.

Implantation of a small-sized biological prosthesis into a hypoplastic aortic annulus causes significant resting gradients. To make insertion of a suitable biological valve possible, we recommend enlargement of the aortic annulus by extension of the aortic incision into the anterior mitral leaflet for approximately 2 cm. A woven Dacron patch is sutured into the V-shaped defect of the anterior mitral leaflet and the aortic ring. This procedure results in enlargement of the aortic circumference of approximately 20 mm. We have applied this technique in 13 patients with severe aortic valvular disease and a hypoplastic aortic annulus. In all patients a prosthesis with a diameter of at least 25 mm could be implanted. The maximal postoperative pressure gradient measured 18 mmHg. There was no early death related to this operative method. All survivors have excellent clinical results with no evidence of mitral regurgitation. This operation represents a practicable alternative method to left ventricular apico-aortic conduit implantation.

Angina pectoris and coronary artery disease in patients with severe aortic valvular disease

We studied the clinical, hemodynamic, and angiographic findings of 90 consecutive patients with significant symptomatic aortic valve disease, 40 years of age or older, to evaluate the prevalence of angina pectoris in relation to coronary artery disease and the effect upon cardiac function. The prevalence of chest pain was 66% (typical angina, 39%; atypical chest pain, 27%), and the prevalence of coronary artery disease was 39%. The prevalence of coronary artery disease in patients with typical angina was 77%, in contrast to 25% in patients with atypical chest pain ( P = 0.001) . Only two of the 35 patients (6%) with coronary artery disease were free of chest pain. Although the incidence of coronary artery disease in patients with aortic stenosis was slightly higher than in patients with aortic regurgitation or aortic stenosis-aortic regurgitation, it was not statistically significant. Patients with aortic regurgitation and coronary artery disease had significantly lower ejection fraction than patients with aortic stenosis and coronary artery disease. There were no significant differences between ejection fraction in patients without coronary artery disease in the different groups. Patients with aortic stenosis and coronary artery disease tend to have lower mean pressure gradients than those without coronary artery disease. Patients with coronary artery disease in aortic regurgitation and aortic stenosis-aortic regurgitation tend to have higher left ventricular end-diastolic pressure. This study indicates that although patients with aortic valve disease and typical angina are most likely to have associated coronary artery disease, it is not possible to predict this disorder with accuracy by means of clinical or hemodynamic findings. Since the presence or absence of coronary artery disease in patients undergoing aortic valve replacement has prognostic and therapeutic significance, we recommend that coronary arteriography be performed in all patients with significant aortic valve disease undergoing cardiac catheterization when they present with any form of chest pain, or in patients over the age of 40 years even if no chest pain is present. Coronary arteriography would also rule out anomalous aortic origin of the coronary arteries.

Noninvasive Tests to Evaluate the Severity of Aortic Stenosis: Limitations and Reliability

Fifty patients were examined with phonocardiograms, carotid pulse tracings, and M-mode echocardiograms to evaluate the ability of noninvasive tests to identify the severity of aortic valvular disease as determined at cardiac catheterization. Linear and multivariate analysis showed these noninvasive approaches to have only fair correlation with the severity of the disease. A binary division of the population under study into severe and nonsevere subgroups based on aortic valvular area (less than or equal to 0.8 sq cm in severe group [n = 25]; greater than 0.8 sq cm in nonsevere group [n = 25]) allowed sensitivity, specificity, and likelihood ratios to be determined. The likelihood ratio increased fourfold as the interval from the ECG Q wave to the murmur's peak (Q-MP) prolonged to 320 msec and increased sevenfold when the rate-corrected left ventricular ejection time (delta LVET) was more than 40 msec beyond values predicted from standard regression equations. Echocardiographic measurements were less helpful. Prolonged values of Q-MP and delta LVET proved to be the best discriminators of severe aortic valvular disease in this population where the prevalence of severe and nonsevere disease was equal.

The prevalence of angina pectoris and abnormal coronary arteriograms in severe aortic valvular disease

In order to relate the frequency of angina pectoris to associated coronary artery disease, 66 consecutive patients with severe aortic valvular disease were studied by cardiac catheterization, including coronary angiography. Angina pectoris was found in 63 per cent of patients with predominant aortic stenosis, 62 per cent with aortic regurgitation, and 67 per cent with mixed disease. Associated coronary artery disease (larger than or equal to 75 per cent luminal stenosis) ranged from 14 to 28 per cent and averaged 20 per cent for the entire group of 66 patients. Only one patient without angina had significant coronary artery stenosis. Our studies indicate that angina pectoris is equally common in all forms of severe aortic valve disease and is usually not associated with significant coronary artery disease.

Calcium in the aortic valve. Roentgenologic and hemodynamic correlations in 148 patients.

The extent of aortic valvular calcification, graded roentgenologically, was correlated with hemodynamic severity as assessed by cardiac catheterization in 148 patients over age 35 who had aortic valvular disease. Each of 55 patients with extensive calcium seen on roentgenogram had severe aortic valvular disease: 29 had stenosis without significant regurgitation, 25 had stenosis and regurgitation, and 1 had pure regurgitation. Many of the 54 patients with small amounts of calcium seen on roentgenogram or with calcium seen only at fluoroscopy had severe aortic valvular disease, but in 12 of them it was hemodynamically mild. Of 39 patients in whom calcium could not be demonstrated either fluoroscopically or on roentgenograms, 12 had severe aortic regurgitation, but only 1 had severe aortic stenosis. The extent of aortic valvular calcification in general correlated with the peak systolic transvalvular pressure gradient but did not correlate with the degree of aortic regurgitation, and calcium was usually absent in patients with pure regurgitation regardless of its severity. Roentgenologic assessment of aortic valvular calcification provides useful information for evaluating patients suspected of having aortic valvular disease.