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Biomedical subjects

J S Rankin

Publications and source records attributed to J S Rankin.

At least 37 records · Page 2Linked to original sources

Comparison of preload recruitable stroke work, end-systolic pressure-volume and dP/dtmax-end-diastolic volume relations as indexes of left ventricular contractile performance in patients undergoing routine cardiac catheterization.

The end-systolic pressure-volume relation, the relation between stroke work and end-diastolic volume, termed the preload recruitable stroke work relation, and the relation between the peak of the first derivative of left ventricular pressure (dP/dtmax) and end-diastolic volume have been employed as linear indexes of left ventricular contractile performance in laboratory animals. The purpose of this study was to examine the relative utility of these indexes during routine cardiac catheterization in seven human subjects (mean age 48 +/- 18 [SD] years) with a normal left ventriculogram and coronary angiogram. Left ventricular pressure was recorded continuously with a micromanometer catheter, and left ventricular volume was derived from digital subtraction contrast ventriculograms obtained at 30-ms intervals. Transient occlusion of the inferior vena cava with a balloon-tipped catheter was employed to obtain beat to beat reductions in left ventricular pressure and volume over 8.7 +/- 1.7 cardiac cycles. Stroke work declined by 49 +/- 13% during vena caval occlusion, but end-systolic pressure fell by only 26 +/- 11%, and changes in dP/dtmax were small and inconsistent (12 +/- 22%). Consequently, the range of data available for determination of the preload recruitable stroke work relation greatly exceeded that for the end-systolic pressure-volume relation and the dP/dtmax-end-diastolic volume relation, and much less linear extrapolation from the measured data was required to determine the volume-axis intercept. Preload recruitable stroke work relations were highly linear (r = 0.95 +/- 0.07), and much more so than end-systolic pressure-volume relations (r = 0.79 +/- 0.23).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography, Digital Subtraction↗

Effects of arterial hypertension on myocardial recovery after ischemic injury.

Although improved surgery, angioplasty, and thrombolysis have made early revascularization of ischemic myocardium commonplace, the effects of arterial hypertension on myocardial recovery remain unclear. Therefore eight conscious dogs were instrumented to measure left ventricular transmural pressure and myocardial segment length in the left anterior descending (LAD) coronary distribution. Reversible ischemic injury was produced by two 15-min LAD occlusions separated by 4 days of reperfusion, with each dog randomly receiving either phenylephrine or placebo infusion for 30 min beginning 1 h after reperfusion. With ischemia, systolic myocardial performance fell to 14.3 +/- 3.7% of control and required greater than 48 h to recover. Compared with placebo, phenylephrine significantly depressed recovery of systolic function assessed by systolic shortening (57 +/- 12 vs. 85 +/- 13% control) or the area under the stroke work vs. end-diastolic length relationship (62 +/- 14 vs. 93 +/- 7% control) (both P less than 0.05). These data imply that ischemically injured myocardium is highly sensitive to arterial hypertension and that ventricular loading is a major determinant of the rate of myocardial recovery.

Animals↗

Observational comparison of event-free survival with medical and surgical therapy in patients with coronary artery disease. 20 years of follow-up.

BACKGROUND: The purpose of this study was to describe the long-term event-free survival patterns of patients with significant coronary artery disease treated medically versus patterns of those treated surgically and to evaluate the factors associated with improved event-free survival. METHODS AND RESULTS: We studied the results of 5,824 patients undergoing medical and surgical therapy for ischemic heart disease from 1969 to 1984, with follow-up to 1991. Events considered for this evaluation were nonfatal myocardial infarction or cardiovascular death. The Cox proportional hazards model was used to determine factors differentially affecting surgical event-free survival. The survival benefits previously reported for bypass surgery in this population were largely preserved when event-free survival was examined. The two factors associated with significant event-free survival benefits for surgically treated patients were more severe coronary artery disease and a more recent surgery data. Patients with more severe coronary obstruction had a greater relative improvement with surgery in event-free survival than did patients with less severe anatomic disease. Event-free survival with surgery progressively improved over the period of the study and, by 1984, was significantly better than medical therapy for most patient subgroups. Patients with poor prognosis because of risk factors such as older age, severe angina, or left ventricular dysfunction had a risk reduction with surgery proportional to their overall risk under medical therapy. CONCLUSIONS: Higher-risk patients with more severe disease (due to either coronary disease or other risk factors and age) should be considered for coronary revascularization because it is in these patients that coronary artery bypass graft surgery has the greatest impact in reducing future cardiovascular events.

Cardiac Catheterization↗

Quantitative analysis of regional wall thickening by transesophageal echocardiography.

To develop a method for quantitative analysis of regional left ventricular function from transesophageal two-dimensional echocardiograms, we conducted studies 10 and 20 minutes after induction of anesthesia in 16 patients with normal hearts who were undergoing minor orthopedic operations. Wall thickening was measured with the centerwall method along 100 chords drawn perpendicular to a line constructed around the center of the ventricular wall, midway between the endocardial and epicardial contours. Thickening, either normalized by the length of the end-diastolic perimeter or expressed as a percentage of the end-diastolic wall thickness at each chord, was compared with measurements of endocardial motion. Wall motion was relatively diminished in the anteroseptal region and enhanced on the contralateral wall, but wall thickening was homogeneous throughout the contour. Normalized wall thickening was significantly less variable (standard deviation/mean, 0.47 +/- 0.13) in the normal population than were either percent wall thickening (0.53 +/- 0.012) or wall motion (0.51 +/- 0.09) (p less than 0.005 for both comparisons). There was no significant change in regional or global function between 10 minutes and 20 minutes after the induction of anesthesia. In summary, normalized wall thickening as a parameter of regional left ventricular function is more homogeneous and less variable in subjects with normal hearts than is endocardial motion because wall thickening measurements are not subject to cardiac translocation artifacts. This low variability suggests that normalized wall thickening measured by the centerwall method may prove particularly useful for intraoperative and postoperative monitoring of regional left ventricular function by transesophageal echocardiography in patients undergoing both cardiac and noncardiac surgical procedures.

Adult↗

Surgical aortic valvuloplasty using the Cavitron Ultrasonic Surgical Aspirator: an invasive hemodynamic follow-up study.

Valve repair and calcium debridement in patients with calcific aortic stenosis, using the Cavitron Ultrasonic Surgical Aspirator (CUSA), results in a reduction in the aortic valve gradient while potentially avoiding long-term problems inherent to prosthetic valves. Invasive followup data in these patients has not previously been reported. Ten patients in whom CUSA debridement was performed underwent cardiac catheterization prior to and 8.0 +/- 2.5 months following the procedure. Compared to baseline, the aortic valve area significantly increased from 0.75 +/- 0.2 to 1.1 +/- 0.3 cm2 (p = 0.009) and the mean gradient was significantly reduced from 54 +/- 21 to 27 +/- 21 mmHg (p = 0.02) at followup. No significant change was noted in cardiac output, ejection fraction, left ventricular end systolic or diastolic volumes or left ventricular end diastolic pressure. However, 6 patients were found to have at least one grade worsening of aortic regurgitation. The development of increased aortic insufficiency in many patients after CUSA aortic valve debridement will likely limit this procedure's clinical utility.

Aged↗

Management and long-term outcome of aortic dissection.

All 163 patients admitted to one institution between 1975 and 1988 with aortic dissection were reviewed. Type I and type II patients received grafting of the ascending aorta, with an intraoperative mortality rate of 11%. For type III dissection, management was medical in 53 patients, while 19 required surgery for aortic rupture or expansion, with an intraoperative mortality rate of 11%. The 9- or 10-year survival rates were 29%, 46%, and 29% for types I, II, and III respectively. Of 135 patients with primary aortic dissection, 17 (13%) required subsequent aortic surgery. Cause of late death was other cardiovascular disease in 38%, rupture of another aortic segment in 18%, sudden death in 24%, and other medical conditions in 21%. Although operative therapy for types I and II dissections and reserving operation for selected type III dissections provides acceptable long-term survival, careful follow-up is necessary due to concurrent cardiovascular disease and residual aortic disease.

Academic Medical Centers↗

Intraoperative transesophageal Doppler color flow imaging used to guide patient selection and operative treatment of ischemic mitral regurgitation.

BACKGROUND: Intraoperative transesophageal Doppler color flow imaging (TDCF) affords the opportunity to assess mitral valve competency immediately before and after cardiopulmonary bypass (CPB). The purpose of this study was to assess the utility of TDCF to assist in the selection and operative treatment of ischemic mitral regurgitation (MR). METHODS AND RESULTS: Two hundred forty-six patients undergoing surgery for ischemic heart disease were prospectively studied. All had preoperative cardiac catheterization. Catheterization and pre-CPB TDCF were discordant in their estimation of MR in 112 patients (46%). Compared with patients in whom both techniques agreed in estimation of MR, patients with discordance in MR were more likely to have had unstable clinical syndromes at the time of catheterization (79% versus 40%, p less than 0.05) or to have received thrombolytics (16% versus 8%, p less than 0.05). Pre-CPB TDCF resulted in a change in the operative plan with respect to the mitral valve in 27 patients (11%). Because less MR was found by TDCF than catheterization, 22 patients had only coronary bypass grafting when combined coronary bypass and mitral valve surgery had been planned. Because more MR was found by TDCF than catheterization, five patients had combined coronary bypass and mitral valve surgery when coronary bypass alone had been planned. Unsatisfactory results noted by TDCF following mitral valve surgery in five patients resulted in immediate corrective surgery. Cox regression analysis identified residual MR at the completion of surgery to be an important predictor of survival (chi 2 = 21.4) after surgery--more important than patient age (chi 2 = 8.3) or left ventricular ejection fraction (chi 2 = 5.3). CONCLUSIONS: These results indicate that TDCF is useful in guiding patient selection and operative treatment of ischemic MR and that in such patients, intraoperative TDCF should be performed routinely.

Adult↗

Diastolic anisotropic properties of the left ventricle in the conscious dog.

The role of myocardial anisotropy in determining change in left ventricular shape during diastolic filling has not yet been demonstrated. Therefore, 11 conscious dogs were instrumented with global ultrasonic dimension transducers to measure left ventricular major and minor axis diameters and equatorial wall thickness. Myocardial geometry was represented as a three-dimensional ellipsoidal shell. Left ventricular transmural pressure was measured with micromanometers, and ventricular volume was varied by inflation of vena caval occluders. Left ventricular wall strains and stresses calculated from the ellipsoidal shell model agreed closely with those measured directly by myocardial force and dimension transducers. Unequal normalized diastolic stress-strain relations were observed in the latitudinal, longitudinal, and wall thickness directions, reflecting anisotropic mechanical properties of the myocardium. Although a greater wall stress in the latitudinal versus longitudinal axis was predicted adequately from left ventricular geometry alone, the observed latitudinal strain exceeded longitudinal strain by an amount greater than was predicted by geometric considerations alone, suggesting that myocardial anisotropy contributes significantly to changes in ventricular shape during diastolic filling.

Animals↗

Aortic dissection resulting from tear of transverse arch: is concomitant arch repair warranted?

Forty-seven patients with aortic dissection resulting from a primary tear located in the transverse aortic arch underwent surgical treatment. Twenty-six patients had acute type A, 7 had acute type B, 7 had chronic type A, and 7 had chronic type B aortic dissections. Of the 33 patients with acute dissections, 11 (7 acute type A and 4 acute type B) underwent concomitant arch repair with an operative (less than or equal to 30 days) mortality rate of 55% (35% to 73%, +/- 1 asymmetric 70% confidence limit) (2 of 7 acute type A and 4 of 4 acute type B). Concomitant arch repair was omitted in 22 patients with acute dissections (19 acute type A and 3 acute type B); the operative mortality rate was 41% (29% to 54%) (7 of 19 acute type A and 2 of 3 acute type B) (p = not significant versus arch repair). The overall survival rate for those with arch repair was 45% +/- 15% (+/- 1 standard error of the estimate) at 4 years, compared with 43% +/- 11% for patients without arch repair (p = not significant). Considering the type of dissection, the 4-year survival estimate for patients with acute type A dissections who underwent arch repair (5 hemiarch and 2 total arch) was 71% +/- 17% (versus 44% +/- 12% for acute type A patients without arch repair). There were no survivors among the 4 patients with acute type B dissections who had an arch repair (1 hemiarch and 3 total arch), whereas patients with acute type B dissections who did not undergo concomitant arch repair had a 4-year survival estimate of 33% +/- 27% (p = not significant versus arch repair). Four other patients with acute type B dissections resulting from an arch tear were managed medically and tended to have a slightly better prognosis (2-year survival estimate of 75% +/- 22% versus 14% +/- 13% for all surgically treated acute type B patients), but again this difference was not statistically significant. Multivariate analysis of the 47 surgical patients revealed that advanced age (p = 0.0008), preoperative dissection complications (p = 0.02), and other coexistent medical problems (p = 0.03) were the only significant, independent determinants of overall mortality. Initial arch repair was not a significant predictor. Nine percent (2/22) of patients with acute type A dissections who initially underwent isolated ascending aortic replacement required subsequent arch replacement; 1 died after reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗

Determinants of early versus late cardiac death in patients undergoing coronary artery bypass graft surgery.

Most analyses of risk factors affecting survival after coronary artery bypass graft surgery have not differentiated among factors that influence early and late survival. For this reason, a multiphase model was applied to survival data from 2,967 patients undergoing a first coronary artery bypass graft at the Duke University Medical Center between 1969 and 1984. There were 709 deaths during follow-up to 19.6 years. The data were analyzed using a multivariable survival model that separates the underlying hazard function into as much as three different phases, each incorporating separate risk factors. Two distinct phases were detected. One phase dominated early survival (0-1 year), and the second phase dominated late survival (greater than 1 year). Surgery performed earlier in our experience was associated with elevated risk of dying in both phases but with different magnitudes, whereas lower ejection fraction, greater extent of coronary disease, older age, conduction abnormality, and history of hypertension were associated with elevated risk of dying similarly in both phases (p less than 0.05). Severity of angina symptoms and lower weight were associated with an elevated risk of dying only in the early phase (p less than 0.05; because few of the patients were obese, estimates of the relative risk of morbid obesity could not be estimated), whereas vascular disease, diabetes, and extent of myocardial damage were associated with an elevated risk of dying only in the late phase (p less than 0.05). These data illustrate both the differential influence of risk factors over time and the importance of multiphase models.

Cohort Studies↗

Influence of diabetes and mammary artery grafting on survival after coronary bypass.

The effect of diabetes on survival after coronary bypass surgery is uncertain. Also, although the overall clinical benefits of internal mammary artery (IMA) grafting are well established, the survival benefit attributable to IMA grafting in diabetics is not well characterized. To determine the influence of diabetes and IMA grafting on survival after bypass surgery in the current surgical era, characteristics related to subsequent outcome were analyzed in 5,654 consecutive patients undergoing surgery in the decade of the 1980s. The 1,132 diabetic patients (20%) had more extensive coronary disease, had more left ventricular dysfunction, were older, were more frequently female, received a greater number of grafts (mean, 3.5 versus 3.1), and received more IMA grafts (67% versus 58%) than the 4,522 nondiabetic patients (all p less than 0.001). Overall 5-year survival probability was 0.91 in nondiabetic and 0.80 in diabetic patients (p less than 0.0001). Nondiabetic survival exceeded diabetic survival even in high-risk subgroups such as ejection fraction less than or equal to 0.40 (0.80 versus 0.66, p less than 0.02), age greater than or equal to 65 years (0.85 versus 0.73, p less than 0.0003), and, urgent surgery (0.89 versus 0.76, p less than 0.0001). By multivariate analysis, impairment of left ventricular function, advanced age, failure to use an IMA graft, diabetes, female sex, urgent surgery, number of diseased vessels, and mitral insufficiency were incremental risk factors for cardiac mortality (all p less than 0.006). Failure to use an IMA graft and diabetes were equally strong predictors of outcome. Use of an IMA graft conveyed an independent survival benefit to both nondiabetic (p less than 0.0001) and diabetic (p less than 0.02) patients. The magnitude of the survival benefit attributable to IMA grafting in the two groups did not differ (p = 0.4). Diabetes is an important risk factor for late cardiac mortality after bypass surgery and should be included in analyses of the efficacy of therapies for coronary artery disease. IMA grafting conveys a similar benefit to diabetic and nondiabetic patients but does not negate the adverse effect of diabetes on survival.

Age Factors↗

Preservation of aortic valve in type A aortic dissection complicated by aortic regurgitation.

Two hundred fifty-two patients underwent operation for type A aortic dissection at Stanford University Medical Center from 1963 to 1987 and Duke University Medical Center from 1975 to 1988. Sixty-seven percent had an acute type A dissection and 33% had a chronic type A dissection. In addition to repair or replacement of the ascending aorta, 121 patients (48%) required an aortic valve procedure. Valve resuspension was performed in 46 (39 acute type A and 7 chronic type A), with an operative mortality rate of 13% +/- 5% (+/- 70% confidence limits), and aortic valve replacement in 75 (36 acute type A and 39 chronic type A), with an operative mortality rate of 20% +/- 5% (p = not significant versus resuspension). The operative mortality rate for patients requiring only repair or replacement of the ascending aorta was 32% +/- 4%. Indications for valve replacement included coexistent (nonacute) aortic valve disease, Marfan's syndrome, annuloaortic ectasia, and cases in which successful resuspension could not be accomplished. The overall actuarial survival rate for all patients was 59% +/- 3% (+/- 1 standard error of the mean), 40% +/- 4%, and 25% +/- 5% at 5, 10, and 15 years, respectively. Survival rates at these same times for patients with valve resuspension were 67% +/- 8%, 52% +/- 10%, and 26% +/- 19%, respectively; for patients who required aortic valve replacement, these survival rates were 70% +/- 5%, 39% +/- 8%, and 21% +/- 11%; finally, patients who received only an ascending aortic procedure had survival probabilities of 51% +/- 5%, 37% +/- 6%, and 23% +/- 6% (p = not significant versus resuspension versus aortic valve replacement). Multivariate analysis showed advanced age (p less than 0.001), previous cardiac or aortic operation (p less than 0.001), more preoperative dissection complications (p = 0.002), and earlier operative date (p = 0.038) to be the only significant, independent factors that increased the likelihood of early or late death. The type of aortic valve procedure (resuspension versus aortic valve replacement versus none) was not a significant predictor of mortality. Two of 46 patients with valve resuspension required late aortic valve replacement (freedom from aortic valve replacement: 100% and 80% +/- 13% at 5 and 10 years, respectively), as did 4 of 75 patients with initial aortic valve replacement (freedom from repeat aortic valve replacement: 98% +/- 2% and 73% +/- 13%, respectively).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

Effects of standard mitral valve replacement on left ventricular function.

Recent studies have suggested that excision of the mitral valve apparatus during mitral valve replacement impairs left ventricular performance. However, functional measurements in humans have been difficult to obtain in a load-independent fashion. To investigate this concept, 12 patients (mean age, 65 +/- 8 years; mean New York Heart Association functional class, 3.3 +/- 0.7) with 4+ mitral regurgitation (n = 8) or mitral stenosis (valve area, 1.2 +/- 0.2 cm2) (n = 4) underwent prosthetic valve replacement using crystalloid cardioplegia. No patient required therapeutic inotropic support, every patient had at least the anterior mitral leaflet excised, and paced heart rate was maintained constant throughout. Left ventricular volume was measured with radionuclide angiocardiography, left ventricular pressure with a 3F micromanometer, and left ventricular wall volume with two-dimensional transesophageal echocardiography. Left ventricular preload was varied over a mean end-diastolic pressure range of 9 to 20 mm Hg and an end-diastolic volume range of 134 to 170 mL to generate four to five steady-state pressure-volume loops before and ten minutes after cardiopulmonary bypass. Left ventricular performance was estimated with the stroke work/end-diastolic volume relationship, which is insensitive to load. After bypass, no significant change (p greater than 0.1) was noted in wall volume for patients with mitral regurgitation or mitral stenosis (175 +/- 68 to 189 +/- 63 mL/m2 and 130 +/- 22 to 127 +/- 19 mL/m2, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

The utility of transesophageal echocardiography and Doppler color flow imaging in patients undergoing cardiac valve surgery.

To assess the value of intraoperative transesophageal echocardiography during cardiac valve surgery, 154 consecutive patients who had a valve operation in conjunction with pre- and postcardiopulmonary bypass transesophageal imaging were studied. Prebypass imaging yielded unsuspected findings that either assisted or changed the planned operation in 29 (19%) of the 154 patients. Imaging immediately after bypass revealed unsatisfactory operative results that necessitated immediate further surgery in 10 (6%) of the 154 patients. Postbypass left ventricular dysfunction, prompting administration of inotropic agents, was identified in 13 patients (8%). Transesophageal echocardiography proved most useful when both two-dimensional and Doppler color flow imaging were employed in patients undergoing a mitral valve operation, where surgical decisions based on echocardiographic results were made in 26 (41%) of 64 cases. Postbypass echocardiographic findings identified patients at risk for an adverse postoperative outcome. Of 123 patients whose postbypass valve function was judged to be satisfactory, 18 (15%) had a major postoperative complication and 6 (5%) died, whereas of 7 patients with moderate residual valve dysfunction, 6 (86%) had a postoperative complication and 3 (43%) died (p less than 0.05 for both). Likewise, of 131 patients with preserved postbypass left ventricular function, 12 (9%) had a major complication and 7 (5%) died, whereas of 23 patients with reduced ventricular function, 17 (73%) had a postoperative complication and 6 (26%) died (p less than 0.05 for both). These data indicate that intraoperative transesophageal echocardiography is useful in formulating the surgical plan, assessing immediate operative results and identifying patients with unsatisfactory results who are at increased risk for postoperative complications.

Cardiopulmonary Bypass↗

Ellipsoidal shell subtraction model of right ventricular volume. Comparison with regional free wall dimensions as indexes of right ventricular function.

Pulse-transit sonomicrometry was used to measure the base-apex (a), anteroposterior (b), and septal-free wall (c) diameters of the left ventricle and the septal-free wall diameter of the right ventricle (d) in eight excised and three isolated, pump-perfused canine heart preparations, as well as in nine conscious dogs. In the three perfused hearts and in four of the excised hearts, right ventricular free wall regional segment lengths and segment area also were assessed. Biventricular volumes were measured directly with intracavitary balloons in all isolated hearts. When left ventricular balloon volume was held constant, relations between right ventricular free wall dimensions and right ventricular balloon volume were highly linear. With increments in left ventricular volume, however, these relations remained linear but shifted progressively upward, indicating an independent relation between right ventricular free wall dimensions and left ventricular cavitary volume. An ellipsoidal shell subtraction model (pi/6.abd minus right ventricular free wall volume) was developed to estimate right ventricular cavitary volume from cardiac dimensions. With this method, a highly linear relation was observed between calculated right ventricular volume and right ventricular balloon volume (mean r = 0.99 +/- 0.01). Moreover, this relation appeared to be independent of changes in left ventricular balloon volume. With the shell subtraction model, dynamic right ventricular volume was computed in nine conscious dogs, and in four, stroke volume derived from dimensions was compared with right ventricular stroke volume measured with ultrasonic flow probes. A highly linear relation was observed, suggesting the accuracy of the shell subtraction method in vivo. Right ventricular end-systolic pressure-volume and stroke work/end-diastolic volume relations then were evaluated, and both proved to be highly linear in the right ventricle (both mean r = 0.99 +/- 0.01). Thus, the shell subtraction model allows a simple estimate of dynamic right ventricular volume in the intact heart and facilitates assessment of right ventricular performance in vivo.

Animals↗

Comparison of medical and surgical therapy for uncomplicated descending aortic dissection.

To guide the choice of medical versus surgical therapy for patients with descending (type B) aortic dissection (tear in the descending aorta without involvement of the ascending aorta), multivariate survival analysis was applied to 136 patients admitted to two medical centers between 1975 and 1988 with acute (n = 89) or chronic (n = 47) descending dissection: group 1, all 136 patients; group 2, 106 patients without rupture, pulse loss, or visceral organ compromise; and group 3, 56 patients from group 2 without major cardiac or renal disease (23 surgical and 33 medical). Group 3 medical and surgical subgroups were well matched for baseline characteristics and were potential candidates for either mode of therapy. By Cox model analysis, significant predictors of mortality were pleural rupture, other dissection complications, increasing age, and cardiac disease (all p less than 0.01). Surgical versus medical therapy was not an independent determinant of survival in any of the three groups for acute or chronic dissection. Survival probabilities for all group 3 patients at 1, 5, and 10 years were 0.94, 0.87, and 0.32 (medical) and 0.90, 0.80, and 0.50 (surgical). Despite the limitations of this retrospective study (including the possibility of undefined treatment selection biases), these data suggest that medical or early surgical therapy is associated with equivalent outcome in selected patients with uncomplicated acute or chronic descending aortic dissection.

Adrenergic beta-Antagonists↗