Perioperative noninvasive cardiac output monitoring in parturients with singleton and twin pregnancies undergoing cesarean section under spinal anesthesia with prophylactic phenylephrine drip: a prospective observational cohort study.

Purpose: Spinal anesthesia is considered the gold standard anesthetic technique for cesarean deliveries (CDs) but is associated with a high rate of hypotension. The recent international consensus recommends continuous prophylactic phenylephrine infusion (PPI) administered throughout CD to prevent hypotension. However, little information is available on the hemodynamic profiles of women with twin pregnancies as compared to singleton pregnancies perioperatively. Therefore, in this study, we aim to compare maternal hemodynamic changes both intraoperatively and postoperatively with the use of the NICAS bioimpendence monitor in healthy singleton versus twin parturients undergoing CD deliveries with spinal anesthesia with PPI. Materials and methods: After IRB approval and signed informed consent, healthy term women with either twin or singleton pregnancies undergoing spinal anesthesia for uncomplicated CD were enrolled. The following data were collected - cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), and total peripheral resistance (TPR). Measurements were measured at five time points: (1) before arrival in OR, (2) after spinal anesthesia with PPI, (3) after beginning of oxytocin infusion, (4) in post anesthesia care room, (5) 24 hours postoperatively, and (6) 48 hours postoperatively. All parturients received standardized spinal solution consisting of 12 mg hyperbaric bupivacaine, 20 µg fentanyl and 100-µg preservative-free morphine. PPI administered was titrated to preserve blood pressure to 20% of baseline blood pressure and stopped at the end of surgery. Oxytocin was administered as a continuous infusion (20-units/1000 cm3 Ringer's lactate) at a rate of 100 cm3/h. Results: One hundred and thirty seven parturients with singleton pregnancies and 27 parturients with twin pregnancies completed the study. There were no significant differences between groups in age or BMI. Intraoperatively, there was no difference in any hemodynamic parameter. However, postoperatively at all three times women with twin pregnancies had higher MAP, lower CO and higher TPR compared with parturients with singleton pregnancies. Conclusions: There were significant hemodynamic changes postoperatively but not intraoperatively in parturients with twin pregnancies compared to women with singleton pregnancies. These changes need to be further investigated.

Intraoperative transesophageal echocardiography during valve replacement surgery. A review.

Intraoperative transesophageal echocardiography (IOTEE) has become an important diagnostic and monitoring tool in the operating theatre during cardiac and noncardiac operations. However, its routine application during valve replacement operations has not received universal recognition. The cumulative experience, brought up in this review, shows that IOTEE is invaluable during valve replacement operations. It has an important role in the consolidation of operative strategy, although it is generally better to obtain all the anatomical and physiological data and the resultant operative strategy in advance, outside the operating room environment. Important data influencing the operative plan has been reported in 3-29% of operations in various studies. The postpump IOTEE is also essential for numerous reasons: it can rule out important misfortunes, such as leaflet immobilization or perivalvular leak, leaky bioprosthesis or coronary obstruction due to valve struts, and is responsible for second pump-run in 3-6% of cases; it is essential in monitoring the deairing process; it provides the surgeon and the anesthesiologist data on biventricular function and volume and exclusion of dynamic left ventricular outflow tract obstruction, and, therefore, guides pharmacotherapy, volume handling and mechanical assistance, including intra-aortic balloon pump indication and location. In conclusion, IOTEE is an essential tool in patients undergoing valve replacement operations, and should be used on a standard basis.

The natural history of aortic valve disease after mitral valve surgery.

OBJECTIVES: The present study evaluates the long-term course of aortic valve disease and the need for aortic valve surgery in patients with rheumatic mitral valve disease who underwent mitral valve surgery. BACKGROUND: Little is known about the natural history of aortic valve disease in patients undergoing mitral valve surgery for rheumatic mitral valve disease. In addition there is no firm policy regarding the appropriate treatment of mild aortic valve disease while replacing the mitral valve. METHODS: One-hundred thirty-one patients (44 male, 87 female; mean age 61+/-13 yr, range 35 to 89) were followed after mitral valve surgery for a mean period of 13+/-7 years. All patients had rheumatic heart disease. Aortic valve function was assessed preoperatively by cardiac catheterization and during follow-up by transthoracic echocardiography. RESULTS: At the time of mitral valve surgery, 59 patients (45%) had mild aortic valve disease: 7 (5%) aortic stenosis (AS), 58 (44%) aortic regurgitation (AR). At the end of follow-up, 96 patients (73%) had aortic valve disease: 33 AS (mild or moderate except in two cases) and 90 AR (mild or moderate except in one case). Among patients without aortic valve disease at the time of the mitral valve surgery, only three patients developed significant aortic valve disease after 25 years of follow-up procedures. Disease progression was noted in three of the seven patients with AS (2 to severe) and in six of the fifty eight with AR (1 to severe). Fifty two (90%) with mild AR remained stable after a mean follow-up period of 16 years. In only three patients (2%) the aortic valve disease progressed significantly after 9, 17 and 22 years. In only six patients of the entire cohort (5%), aortic valve replacement was needed after a mean period of 21 years (range 15 to 33). In four of them the primary indication for the second surgery was dysfunction of the prosthetic mitral valve. CONCLUSIONS: Our findings indicate that, among patients with rheumatic heart disease, a considerable number of patients have mild aortic valve disease at the time of mitral valve surgery. Yet most do not progress to severe disease, and aortic valve replacement is rarely needed after a long follow-up period. Thus, prophylactic valve replacement is not indicated in these cases.

Persistent ST segment depression in precordial leads V5-V6 after Q-wave anterior wall myocardial infarction is associated with restrictive physiology of the left ventricle.

OBJECTIVES: To examine the relationship between the persistence of ST segment depression in leads V5-V6 after Q-wave anterior wall myocardial infarction (MI) and the filling pattern of the left ventricle (LV). BACKGROUND: Precordial ST segment depression predominantly in leads V5-V6 is associated with increased in-hospital morbidity and mortality after acute myocardial ischemia, perhaps due to reduced diastolic distensibility of the LV. METHODS: We prospectively studied 19 patients after Q-wave anterior wall MI (>6 months). All patients underwent 12-lead ECG recording, symptom-limited treadmill exercise testing with single photon emission computed tomography thallium-201 imaging, transthoracic Doppler echocardiography, cardiac catheterization and measurement of circulating atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels. Patients were classified based on the presence of ST segment depression in leads V5-V6: Group I = ST segment depression <0.1 mV (n = 10); Group II = ST segment depression > or =0.1 mV (n = 9). RESULTS: Patients in Group II had greater LV end diastolic pressures (32.4 +/- 6.5 mm Hg vs. 14.8 +/- 6.1 mm Hg; p = 0.0001), higher plasma ANP (44.4 +/- 47.1 pg/ml vs. 10.7 +/- 14 pg/ml; p = 0.04) and BNP levels (89.4 +/- 62.7 pg/ml vs. 23.6 +/- 33.1 pg/ml; p = 0.01), greater left atrium area (20.6 +/- 3.1 cm2 vs. 17.8 +/- 2.4 cm2; p = 0.05), lower peak atrial (A), higher early (E) mitral inflow velocities, a higher E/A ratio and a lower deceleration time (167 +/- 44 ms vs. 220 +/- 40 ms; p = 0.05). Lung thallium uptake during exercise was more common in Group II (78% vs. 10%, p = 0.04). CONCLUSIONS: Persistent ST segment depression in leads V5-V6 in survivors of Q-wave anterior wall MI is associated with increased LV filling pressure and a restrictive LV filling pattern.

Thrombolysis is an effective and safe therapy in stuck bileaflet mitral valves in the absence of high-risk thrombi.

OBJECTIVES: We sought to evaluate the effectiveness and safety of thrombolytic therapy in stuck mitral bileaflet heart valves in the absence of high-risk thrombi. BACKGROUND: Current recommendations for the thrombolytic treatment of stuck prosthetic mitral valves are partially based on older valve models and inclusion of patients in whom high-risk thrombi were either ignored or not sought for. The feasibility and safety of thrombolysis in bileaflet models may be affected by the predilection of thrombi to catch the leaflet hinge. METHODS: We studied 12 consecutive patients (men/women = 5/7, age 58.8 +/- 14.9 years) who experienced one or more episodes of stuck bileaflet mitral valve over a 33-month period and received thrombolytic therapy with streptokinase, urokinase or tissue-type plasminogen activator. Transesophageal echocardiography was performed in all patients. Patients with mobile or large (>5 mm) thrombi were excluded. Functional class at initial episode was I-II in 4 patients (33.3%) and III-IV in 8 patients (66.6%). RESULTS: Patients receiving thrombolytic therapy achieved an overall 83.3% freedom from a repeat operation or major complications (95% confidence interval 51.6-97.9%). Minor bleeding occurred in three patients (25%) and allergic reaction in one (8.3%). Transient vague neurologic complaints, without subjective findings, occurred in four patients (33.3%). Three patients had one or more relapses within 5.2 +/- 3.1 months from the previous episode, and readministration of thrombolytics was successful. CONCLUSIONS: In clinically stable patients with stuck bileaflet mitral valves and no high-risk thrombi, thrombolysis is highly successful and safe, both in the primary episode and in recurrence. The best thrombolytic regimen is yet to be established.

The safety and efficacy of repeated courses of tissue-type plasminogen activator in patients with stuck mitral valves who did not fully respond to the initial thrombolytic course.

In carefully selected patients with stuck mitral valves, thrombolytic therapy is becoming an established therapeutic modality. However, the management of patient with a suboptimal response to an initial thrombolytic course is unclear. The objective was to evaluate the efficacy and safety of re-administration of tissue-type plasminogen activator (rt-PA) in patients with stuck mitral valves in whom the first thrombolytic course has failed to restore normal prosthetic valve function. The study group included patients who received rt-PA and did achieve a full restoration of valve function after the initial course. Data were gathered on the safety and success rates of additional thrombolytic courses in the same hospitalization period, and their predictors. Twelve patients with stuck mitral valves experienced a total of 13 episodes in which a full resolution of leaflet abnormality was not achieved after the initial thrombolytic course. A repeated thrombolytic course was attempted in 10 patients (11 episodes). Six patients (60%) showed full success rate with repeated thrombolysis, one (10%) showed partial success, and three patients (30%) had no improvement following the second course. These last three were those with initial failure. Age, gender, valve model, worst functional class, time since valve implantation and International Normalized Ratio (INR) levels were similar in both groups. No major adverse events were noted. In this small group of patients with stuck mitral valves, re-administration of rt-PA after a partial response to an initial thrombolytic course was effective and safe. However, total failure of the first thrombolytic course predicted inefficiency of further courses.

Association between mitral annulus calcification and aortic atheroma: a prospective transesophageal echocardiographic study.

BACKGROUND AND PURPOSE: Although mitral annulus calcification (MAC) has been reported to be a significant independent predictor of stroke, no causative relationship was proven. It is also known that aortic atheroma (AA), especially those >/=5 mm thick and/or protruding and/or mobile are associated with stroke. This study was designed to determine whether an association exists between MAC and AA. METHODS: We prospectively evaluated the records of 279 consecutive patients who underwent transesophageal echocardiography (TEE) for various indications to measure the presence and characteristics of AA. The 105 patients in whom a diagnosis of MAC was made on transthoracic echocardiography (TTE) immediately preceding the TEE, were compared with 174 age-matched patients without MAC. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. We measured MAC thickness with two-dimensional-TTE in four-chamber view and AA thickness, protrusion and mobility with TEE. AA was defined as localized intimal thickening of >/=3 mm. A lesion was considered complex if there was plaque extending >/=5 mm into the aortic lumen and/or if it was protruding, mobile or ulcerated. RESULTS: No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the MAC group for prevalence of AA (91 vs. 44%, P<0.001), atheromas >/=5 mm thick (68 vs. 19%, P<0.001), protruding atheromas (44 vs. 15%, P<0.001), ulcerated atheromas (10 vs. 1%, P<0.001) and complex atheroma (74 vs. 22%, P<0.001). Sixty patients had MAC thickness >/=6 mm and 45<6 mm. AA thickness was significantly greater in the patients with a MAC thickness of >/=6 mm (6.1+/-2.8 vs. 5.0+/-2.6 mm, P=0.03). On multivariate analysis MAC, hypertension and age were the only independent predictors of AA (P=0.0001, 0.005 and 0.007, respectively). CONCLUSIONS: There is a significant association between the presence and severity of MAC and AA. MAC may be an important marker for atherosclerosis of the aorta. This association may explain in part the high prevalence of systemic emboli and stroke in patients with MAC.

Electrocardiographic criteria for predicting the culprit artery in inferior wall acute myocardial infarction.

Two patterns of the QRS complex in the lateral lead aVL on the admission electrocardiograms of patients with inferior wall acute myocardial infarction (AMI) were correlated with the culprit artery. S/R wave ratio < or =1/3 with ST depression < or =1 mm was found to be a sensitive and specific marker for left circumflex artery AMI, whereas S/R-wave ratio >1/3 with ST-segment depression >1 mm was suggestive of right coronary artery AMI.

Nonobstructive aortic valve calcium as a window to atherosclerosis of the aorta.

Aortic valve calcium without stenosis and mitral annulus calcium (MAC) are known to correlate with atherosclerotic risk factors. Recently, it has been reported that MAC is associated with atherosclerosis of the cardiovascular system, suggesting MAC as an atherosclerotic process by itself. Hence, the aim of the present study was to determine whether a similar association between aortic valve calcium and aortic atheroma exists. Ninety-six patients (54 men and 42 women, mean age 72 +/- 12 years) with aortic valve calcium who underwent transesophageal echocardiography (TEE) formed the study group. They were compared with 92 sex- and age-matched patients without aortic valve calcium who underwent TEE for the same indications during the same period. The presence and echocardiographic features of aortic atheromas were evaluated by TEE. No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the aortic valve calcium group for prevalence of aortic atheroma (86% vs 30%, p = 0.001). This significant trend was also consistent with the dimension and complexity of the atheromas. On multivariate analysis aortic valve calcium, and MAC were the only independent predictors of aortic atheroma (p = 0.0001, 0.006 respectively). We conclude that there is a significant association between the presence of aortic valve calcium and the presence and severity of aortic atheroma. Thus, aortic valve calcium may serve as a window to atherosclerosis of the aorta.

Relation of nonobstructive aortic valve calcium to carotid arterial atherosclerosis.

Recently it was shown that subjects with aortic valve calcium (AVC) are at increased risk for future cardiovascular disease including stroke. We hypothesized that the increased risk of stroke may be due to an association with carotid artery atherosclerotic disease. Between 1995 and 1999 our laboratory made a diagnosis of AVC without significant stenosis in 3,949 patients. Of those, 279 patients without other cardiac structural exclusion criteria (148 men and 131 women; mean age 73 +/- 9 years, range 45 to 90) underwent carotid artery duplex ultrasound for various indications, and formed the study group. Age- and sex-matched patients without AVC (n = 277), who underwent carotid artery duplex ultrasound during the same period and for the same indications, served as the control group. Compared with the control group, the AVC group had a significantly higher prevalence of carotid stenosis (> 40% to 60%, 89% vs 78% [p < 0.001]; >60% to 80%, 43% vs 23% [p <0.001];and > 80% to 100%, 32%vs 14% [p < 0.001]). The AVC group had a similar, significantly higher prevalence of > or = 2-vessel disease and bilateral carotid stenosis (stenosis levels of > 20% to 40%, >40% to 60%, > 60% to 80%, and > 80% to 100%). In multivariate analysis, AVC, but not traditional risk factors, was the only independent predictor of severe carotid atherosclerotic disease (stenosis > 80% to 100%; p = 0.0001). Thus, there is a significant association between the presence of AVC and carotid atherosclerotic disease.

Mitral annular calcium detected by transthoracic echocardiography is a marker for high prevalence and severity of coronary artery disease in patients undergoing coronary angiography.

This study tests the hypothesis that mitral annular calcium (MAC) detected by transthoracic echocardiography (TTE) is a marker for high prevalence and severity of coronary artery disease (CAD) in patients undergoing coronary angiography. Pathological studies have suggested that there is an association between MAC and calcific deposits in coronary arteries; however, there are no clinical data to support this association. One hundred sixty-five patients with MAC (101 women and 64 men; mean age 71 +/- 8 years) who underwent cardiac catheterization with coronary angiography for various reasons were compared with 147 age-matched controls without MAC who underwent coronary angiography for the same indications during the same period. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet detected by TTE. Obstructive CAD was defined as either > or = 50% reduction of the internal diameter of the left main coronary artery or > or = 70% reduction of the internal diameter of the left anterior descending, right coronary, or left circumflex artery distribution. Compared with controls, the MAC group had a significantly higher prevalence of CAD (89% vs 75%, p = 0.001) and higher rates of 3-vessel disease (45% vs 24%, p = 0.001) and left main CAD (13% vs 5%, p = 0.009). Nonsignificant CAD was more common in the control group (25% vs 11%, p = 0.001). Multivariate analysis identified MAC (p = 0.0002), indications for cardiac angiography (p = 0.02), sex (p = 0.03), and diabetes mellitus (p = 0.03) as independent predictors for the presence and severity of obstructive CAD. MAC detected by TTE may be a marker for high prevalence and severity of CAD in patients undergoing coronary angiography.

Association between mitral annular calcium and aortic atheroma as detected by transesophageal echocardiographic study.

Significant association was found between the presence of mitral annular calcium (MAC) and aortic atheroma detected by transesophageal echocardiography. MAC may be an important marker for aortic atherosclerosis.

There is synergism between high-intensity, low-frequency ultrasound and streptokinase but not with eptifibatide, heparin, and aspirin. Differential effects on fresh and aged blood clots. An in vitro study.

OBJECTIVE: Ultrasound is emerging as a promising modality for recanalization of acutely thrombosed blood vessels, especially when associated with fibrinolytics. We assessed the efficacy of ultrasound combined with saline, heparin, eptifibatide, aspirin, and streptokinase in disruption of fresh as well as aged human blood clots, using an in vitro model. METHODS: Blood clots from five donors, 2-4 or 48 hours old, were cut into 250-400 mg slices and immersed for 1, 15, or 30 min in 10 ml saline containing either heparin, eptifibatide, aspirin, streptokinase, or saline alone. Clots were then randomized to 10 s of 20 kHz ultrasound or immersion alone. After treatment, the percentage difference in weight was calculated. RESULTS: Immersion of fresh clots without ultrasound in eptifibatide and heparin resulted in significantly more clot lysis than immersion in saline, aspirin, and streptokinase. Immersion of aged thrombi without ultrasound in heparin, eptifibatide, and aspirin had no additive effect over immersion in saline. Ultrasound enhanced clot disruption in all five solutions, in each immersion time and both in fresh and aged clots. Heparin and aspirin had no additive effect, compared with saline, on ultrasound disruption of both fresh and aged clots, whereas eptifibatide was less effective than saline. In contrast, streptokinase greatly enhanced disruption of both fresh (P=.004) and aged (P<.001) thrombi by ultrasound. The combinations of ultrasound with saline, heparin, eptifibatide, and aspirin were less effective on aged than fresh thrombi, whereas the combination of ultrasound with streptokinase was equally effective on fresh and aged thrombi. CONCLUSIONS: Using a simple in vitro model, we found that the combination of streptokinase and low-frequency ultrasound had a synergistic effect on disruption of both fresh and aged blood clots. Further studies are needed to assess the role of heparin and antiplatelet agents in augmenting clot disruption by ultrasound in in vivo models of acute and subacute thrombosis.

Evaluation of tricuspid regurgitation severity: echocardiographic and clinical correlation.

The correlation between 19 echocardiographic markers of tricuspid regurgitation (TR) severity and findings on physical examination was studied in 66 consecutive patients (age 63 +/- 12 years) with moderate or severe TR. Clinical TR was defined by two or more of the following: prominent jugular venous pulse V waves, pulsating liver, and sea-saw parasternal movement. Thirty-eight patients (57.6%) had clinical TR, whereas 28 patients (42.4%) did not. In a univariate analysis, the most powerful predictors of clinical TR (p < 0.01) were jet area > or =9 cm2, right atrial area > or =30 cm2, jet width at origin > or =0.8 cm, systolic flow reversal in the hepatic veins, paradoxical septal movement, diastolic septal flattening, inferior vena cava diameter > or =2.1 cm, and lack of inferior vena cava respiratory variation. Regurgitant index was a weaker predictor. Multivariate analysis showed that the only independent echocardiographic predictor of clinical TR was systolic flow reversal (positive and negative predictive values 91.2% and 78.1%, respectively). Significant echocardiographic TR can be subclinical in a substantial number of patients.

Correlation between electrocardiographic subtypes of anterior myocardial infarction and regional abnormalities of wall motion.

BACKGROUND: Examination of the electrocardiogram is the most widely used means for diagnosis and early stratification of risk of acute myocardial infarction (AMI). The classical classification of the subtypes of anterior AMI is based on results of studies comparing the electrocardiograms recorded at various stages, mostly in the subacute or chronic stage of AMI, with autopsy findings. Reports regarding the correlation between electrocardiographic findings in the acute phase and regional abnormality of wall motion (AWM) detected by echocardiographic evaluation are sparse. OBJECTIVE: To investigate the relationship between the electrocardiographic and two-dimensional echocardiographic findings regarding patients with their first anterior AMI. DESIGN AND METHODS: We studied 58 patients, 44 men and 14 women of mean age 61.5 +/- 14.6 years, with their first anterior AMI who had undergone two-dimensional echocardiographic evaluation within 48 h of admission. Deviation of ST-segment trace from baseline was measured manually 0.06 s after the J point for all leads on the admission electrocardiogram. ST-segment elevation in the various leads was correlated to the incidence of regional AWM detected by echocardiography. RESULTS: ST-segment elevations > or = 0.1 mV in V1 leads were found for 21 (36.2%) patients. Basal anterior, basal anteroseptal, and basal septal AWM were seen more often for patients with than they were for patients without ST-segment elevation in V1 (57 versus 16%, P=0.003; 43 versus 13.5%, P=0.03; 43 versus 11%, P=0.01 respectively). In contrast to ST-segment elevation in lead V1, the only statistically significant difference in prevalence in the presence of regional AWM between patients with (n = 48) and without (n = 10) ST-segment elevation > or = 0.2 mV in lead V2 was in the inferoapical region (87.5 versus 40%; P=0.003). ST-segment elevation > or = 0.1 mV in leads aVL and V5 was found for 11 (19%) and 23 (40%) patients, respectively. There was no correlation between either lateral or apical regional AWM and the presence of ST-segment elevation in the anterolateral leads except for mid-lateral AWM, which was more often detected for patients with than it was for patients without ST-segment elevation in aVL leads (36.3 versus 6.4%, P=0.026). CONCLUSIONS: ST-segment elevation in lead V1 during the acute phase of anterior AMI is associated with a high incidence of regional AWM in the basal anterior, anteroseptal, and anterior regions, whereas ST-segment elevation in lead V2 is more often associated with AWM in the inferoapical region. ST-segment elevation in aVL leads is related to mid-lateral regional AWM.

Automatic assessment of cardiac function from short-axis MRI: procedure and clinical evaluation.

Cardiac magnetic resonance imaging (MRI) provides a wealth of morphological and physiological information. Automatic extraction of this information is possible by implementing various image processing techniques. However, existing procedures mostly rely on extensive human interaction and are seldom evaluated on a clinical scale. In this study, a nearly automatic process that extracts physiological parameters from cardiac MR images has been both developed and clinically evaluated. Raw images were obtained in the short-axis view and acquired by a gradient-cho (GE) protocol. In images selected to be analyzed, the only manual step required is the indication of a point in the center of the left ventricle (LV). From a set of such images, the process extracts endocardial and epicardial contours and calculates left ventricular volumes, mass and ejection fraction (EF). The process implements novel approaches to image processing techniques such as thresholding and shape extraction and can be adapted to other acquisition protocols. The process has demonstrated a clear potential for accurate extraction of the endocardial contour but a lower one with respect to the epicardial contour as a result of the low contrast between myocardium and some surrounding tissues, generated by the gradient-echo protocol. The ability of the process to asses physiological parameters has been subjected to a systematic clinical evaluation, which compared parameters, derived manually and automatically, in 10 healthy subjects and 10 patients. The evaluation has indicated that although individual volumes and mass were not accurately assessed, the automatic process has shown high potential for assessing the ejection fraction with relatively high accuracy and reliability.

Anticoagulant management of patients with mechanical prosthetic valves undergoing non-cardiac surgery: indications and unresolved issues.

A wide array of recommendations is available for the management of anticoagulation in patients with a prosthetic heart valve scheduled for non-cardiac surgery, ranging from avoidance of replacement anticoagulant therapy in all cases (excluding those with a recent thromboembolic event), to replacement anticoagulant therapy in all, without risk stratification. These guidelines are derived from only a few small- to medium-sized, non-randomized and often methodologically flawed studies conducted during the late 1970s, and applies mainly to caged-ball and caged-disc valves. Furthermore, extrapolation of the thromboembolic risk from data on patients not receiving oral anticoagulants at all is based on assumptions that are not necessarily valid. In this review, the direct and indirect evidence on which these guidelines are based is examined critically. Their applicability to the newer, less thrombogenic valve models is questionable. The need for further prospective, randomized studies is emphasized by the failure of existing studies to adjust properly for the main known or presumed thromboembolic risk factors, and their low statistical power to detect significant differences between protocols in an intention-to-treat manner. The evaluation of obstructive and non-obstructive thrombosis should serve as a secondary outcome measure in the assessment of anticoagulation management before non-cardiac surgery.

Mid-term clinical and echocardiographic follow up of patients with CarboMedics valves in the tricuspid position.

BACKGROUND AND AIM OF THE STUDY: Debate continues regarding tricuspid valve replacement (TVR) with a mechanical prosthesis. Experience with bileaflet prostheses is limited; hence the study aim was to explore early and mid-term outcome and hemodynamic data in patients with bileaflet CarboMedics prosthetic valves in the tricuspid position. METHODS: The study population included 25 patients (21 females, four males; mean age 50.5 +/- 13.4 years) who underwent TVR with a CarboMedics valve over a six-year period. Routine clinical examinations and details of transthoracic echocardiography (TTE) were reviewed. Additional TTE, transesophageal echocardiography (TEE) and fluoroscopy were performed as indicated. The number of previous cardiac operations was zero, one and two in 36%, 32% and 32% of patients, respectively. Previous tricuspid surgery was performed in eight cases (32%); concurrent mitral valve replacement was performed in 17 (68%). The hospital mortality rate was 24% and late mortality rate 12%. Seventeen early survivors (13 females, four males) were followed up for 46 +/- 28 months (range: 4-96 months). RESULTS: Among early survivors, the mean and peak transvalvular gradients were 4.0 +/- 1.7 and 7.9 +/- 3.3 mmHg, respectively. Commonly observed INR levels were >2.5 in seven patients (41%), and >3.0 in only three (18%). Five patients (29% of mid-term survivors) experienced a total of 13 episodes of obstructive valve thrombosis, mostly with inappropriate anticoagulation. One patient required emergency re-do surgery; the others responded initially to thrombolysis or intensified antithrombotic treatment, but experienced at least two additional relapses. Aside from thrombotic episodes, all patients but two were in NYHA functional class II-III, and all but four required diuretics. CONCLUSION: TVR with bileaflet mechanical valves carries a high perioperative mortality and mid-term morbidity. Among patients with poor or fair anticoagulation, these valves were associated with a high incidence of obstructive valve thrombosis. If poor patient compliance is anticipated, insertion of a bioprosthesis should be encouraged.

Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement.

BACKGROUND AND AIM OF THE STUDY: The association between mitral valve disease and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MVR) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conducted to evaluate these issues. METHODS: Eighty-six patients (26 men, 60 women) who underwent MVR were evaluated by transthoracic echocardiography. Fifty-nine patients had chronic AF (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurgitation, and presence and duration of AF. Peak and mean transprosthetic mitral valve gradients and pulmonary pressure were estimated by Doppler echocardiography. RESULTS: Groups were matched for age, sex and time from MVR (mean 6.6 years). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitral valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11+/-12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8+/-0.8 versus 1.1+/-0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis identified AF as a single predictor of NYHA class after MVR. Although left and right atrial areas were larger in AF patients (47+/-25 versus 27+/-7 cm2, p = 0.0001 and 30+/-12 versus 17+/-5 cm2, p = 0.0001, respectively), the left:right atrial size ratio was not significantly different between groups. Multivariate analysis identified mean transmitral gradient and duration of AF as independent predictors of left atrial size after MVR (p = 0.01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p = 0.003 and p = 0.0001, respectively). CONCLUSION: The presence of AF after MVR is associated with a worse NYHA functional class, increased transmitral gradients, and larger areas of both atria, when compared with sinus rhythm. Hence, a special effort should be made to correct arrhythmia during surgery, and in case of paroxysmal arrhythmia, earlier surgery should be considered before the condition becomes chronic.

Tricuspid regurgitation late after mitral valve replacement: clinical and echocardiographic evaluation.

BACKGROUND AND AIM OF THE STUDY: Significant tricuspid regurgitation (TR) can contribute to increased morbidity and mortality in patients after mitral valve replacement (MVR), both in the immediate and late postoperative period. The aim of this study was to evaluate the prevalence and the clinical importance of TR late after MVR, as assessed both clinically and echocardiographically. METHODS: The study group comprised 65 patients (39 women, 26 men; mean age 61+/-12 years) with rheumatic heart disease who had undergone MVR without tricuspid valve surgery between one and 30 years (mean 11.3+/-8 years) before their last clinical examination. All patients underwent a complete color-Doppler echocardiographic examination. The predominant presurgical mitral lesion was stenosis in 44 patients and regurgitation in 21. The severity of the tricuspid valve disease was assessed echocardiographically using color-Doppler flow images and flow direction in the inferior vena cava or hepatic veins, and by clinical evaluation. RESULTS: Echocardiography revealed significant late TR in 44 patients (67%), which was moderate in 16 and severe in 28, and evident on physical examination in 24 cases (37%). Age (relative risk (RR) = 1.1; C.I. 1-1.1) and female sex (RR = 1.8; C.I. = 1.0-3.2) were identified as statistically significant predictors for late clinical TR development, but only age was found as a statistically significant predictor for echocardiographic TR development. An elevated RR for organic TR and predominant mitral regurgitation was found. In contrast, pre- and postoperative pulmonary artery pressure, predominant mitral lesion, prosthetic valve gradient and regurgitation were similar in patients with and without late TR. CONCLUSIONS: Significant TR diagnosed by echocardiography late after MVR is common, and clinically evident in more than one-third of patients. Therefore, a lower threshold for tricuspid valve repair should be considered when mitral valve surgery is carried out.