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Biomedical subjects

H B Barner

Publications and source records attributed to H B Barner.

At least 91 records · Page 5Linked to original sources
PubMed1988

The changing profile of the patient undergoing coronary artery bypass surgery.

The first 100 consecutive patients undergoing isolated coronary artery bypass surgery in 1975 were evaluated with respect to the incidence of operative risk factors and outcome. When compared with an identically selected group from 1985, there was significant worsening of the preoperative condition over the decade with regard to mean age (p less than 0.0005), presence of congestive heart failure (p less than 0.05), left ventricular dysfunction (p less than 0.05), severity of coronary artery disease (p less than 0.001) and incidence of emergency operation (p less than 0.05). More patients in 1985 had associated medical diseases such as diabetes (p less than 0.01) and chronic lung disease (p less than 0.005). There was an increase in the occurrence of vascular diseases (hypertension, renal dysfunction, peripheral vascular and cerebrovascular disease) (p less than 0.05). Overall operative mortality increased from 1 to 8% (p less than 0.05) over the decade. Despite the deterioration in the clinical profile of the patient undergoing coronary bypass surgery, elective procedures were still performed with low mortality. The significant increase in overall mortality was chiefly in patients undergoing emergency operation (p less than 0.05). There were also increases in operative morbidity including low output syndrome (p less than 0.01) and respiratory (p less than 0.005) and neurologic (p = 0.06) complications.

Age Factors↗
PubMed1988

The changing mortality of myocardial revascularization: coronary artery bypass and angioplasty.

The risk factors and outcome for the first 150 consecutive patients undergoing coronary artery bypass grafting (CABG) in 1985 (CABG '85) were compared with those of the first 150 patients undergoing CABG in 1975 (CABG '75) and those of the first 150 patients to have percutaneous transluminal coronary angioplasty (PTCA) in 1985 (PTCA '85). The CABG '85 patients had a significantly higher (p less than 0.05) incidence of known operative risk factors including advanced age, female sex, severity of angina, history of recent infarction, triple-vessel disease, left ventricular dysfunction, and emergency operation than the CABG '75 cohort. The clinical profile of the PTCA '85 patients closely resembled the low-risk profile found in the CABG '75 patients. Overall mortality following CABG more than doubled during the decade studied (3% versus 7%, p = 0.07). This study suggests that the increased mortality associated with CABG in 1985 is due in part to the inclusion of more high-risk patients in the surgical population. In addition, the application of PTCA removes low-risk patients from the surgical candidate pool and adds more patients requiring emergency operations, thereby further contributing to the overall decline in the clinical status of patients referred for operation.

Age Factors↗
PubMed1988

Coronary ostial stenosis.

From January 1970 to December 1986, 2.7% (228/8509) of all patients having coronary artery bypass grafting had atherosclerotic coronary ostial stenosis of 50% or more. There were 126 males (55%) and 102 females (45%) with mean ages of 60.2 +/- 9.0 and 59.2 +/- 10.2 years (P = NS), respectively. The left ostium was involved in 176 (77.2%) patients, the right in 41 (18.0%) and both in 11 (4.8%). Isolated ostial stenosis (no associated coronary disease of 50% or more) was present in 38/228 (17%) with females predominating (29/38, 76%). Isolated ostial stenosis occurred more frequently on the right (10/41, 25%) than on the left (18/176, 16%). Associated coronary disease occurred in a single vessel in 42 patients, in two vessels in 72 and in three vessels in 76 resulting in a mean of 2.0 diseased vessels per patient. If patients with isolated ostial stenosis are excluded there were 2.3 diseased arteries per patient. There were 687 grafts performed in these patients, an average of 2.3 grafts per patient. One month surgical mortality was 4.8% (11/228), but has been 2% (2/104) in the last 4 years. Nine of 27 late deaths were noncardiac with a mean follow-up of 49 +/- 44 months. Ostial stenosis is hemodynamically equivalent to left main disease when the left ostium is involved. Symptomatic ostial lesions, whether right or left, require operative therapy.

Adult↗
PubMed1988

Seven years' experience with the Pierce-Donachy ventricular assist device.

Of currently available methods for mechanical circulatory support, the Pierce-Donachy external pneumatic ventricular assist device has proved to be one of the most versatile and effective. Since 1981, 48 patients, aged 15 to 71 years (mean 43.0), with profound cardiogenic shock refractory to conventional therapy with drugs and intra-aortic balloon support, were supported with the Pierce-Donachy ventricular assist device. There were four patient groups. The largest group consisted of 30 patients with cardiogenic shock after cardiac operations. Nine required left ventricular support, six needed right ventricular support plus an intraaortic balloon pump, and 15 had biventricular support. Duration of support ranged from 3 hours to 22 days (mean 3.6 days). Eight of the first 11 patients died in the operating room of bleeding and/or biventricular failure. However, 16 patients, (53%) had improved cardiac function, 15 (50%) were weaned, and 11 (36%) were discharged. Of the last 19 patients, 47% survived. Frequent factors in nonsurvivors were myocardial infarction (75%) and renal failure (90%). Common complications in all patients were bleeding (52%) and infection (27%). The second group consisted of 11 patients with end-stage cardiomyopathy or acute myocardial infarction in whom the Pierce-Donachy ventricular assist device was used as a bridge to transplantation (left ventricular support, four patients; biventricular support, seven patients). Renal failure, infection, or coagulopathy that precluded transplantation developed in five patients. Five patients were supported for 8 hours to 75 days (mean 20.7 days) before undergoing successful transplantation, with one late death (six months) from rejection owing to noncompliance. One has subsequently undergone successful transplantation after 84 days of support. The third group consisted of four patients, aged 40 to 56 years (means 47.2), who had refractory cardiogenic shock after cardiac transplantation caused by pulmonary hypertension (two patients), hyperacute rejection (one patient), or graft failure (one patient). Despite biventricular support in all four (biventricular assist devices, two patients; right ventricular assist device plus intraaortic balloon pump, two patients), all died of infection and/or renal failure after 12 hours to 6 days (mean 3.4 days) of support. The final group consisted of three patients, aged 36 to 51 years (mean 45), with cardiogenic shock caused by acute myocardial infarction. One patient was supported with biventricular assist devices (3.5 days) and two patients were supported with a left ventricular assist device (8.5 and 15 days).(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1988

Coronary artery bypass for recent infarction. Predictors of mortality.

The role of coronary artery bypass (CAB) surgery in patients with recent myocardial infarction remains controversial. To more clearly define the operative risks, we reviewed 336 patients who underwent isolated CAB within 30 days of infarction. There were 129 patients with stable or no angina (Group 1), 163 with angina at rest (Group 2), 21 with angina requiring intra-aortic balloon counterpulsation for pain control (Group 3), and 23 with severe postinfarction ischemia or extension complicated by cardiogenic shock (Group 4). There were 26 (7.7%) deaths overall. The mortality was 2.3% in Group 1, 6.1% in Group 2, 9.5% in Group 3, and 47.8% in Group 4. Univariate analysis (Student's t and chi 2 tests) and multivariate analysis (stepwise logistic regression model) were performed on 17 variables: age, gender, clinical Group (1-4), number of diseased vessels, presence of left main artery disease, left ventricular wall-motion score, left ventricular end-diastolic pressure, presence of mitral insufficiency, extent of infarction (subendocardial vs. transmural), interval from infarction to CAB, number of distal anastomoses performed, preoperative hemodynamic status, aortic cross-clamp time, and total cardiopulmonary bypass time. Only advanced age (p = 0.002), left ventricular wall-motion score (p = 0.004), and clinical group (p = 0.048) proved to be independent predictors of mortality by multivariate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Coronary artery bypass surgery in patients aged 80 years or older.

Between August 1980 and January 1986, 23 patients aged 80 years or older underwent coronary artery bypass grafting (CABG) operations. These patients had a higher incidence of severe left main coronary artery narrowing (p less than 0.0001), 3-vessel coronary artery disease (p less than 0.05) and moderate to severe left ventricular dysfunction (p less than 0.05) than patients in the Coronary Artery Surgery Study registry older than 65 years. Of 14 patients undergoing elective simple CABG procedures, none died; of 19 elective cases overall, 2 patients died (11%). Three of 4 patients undergoing emergency procedures (75%) and 4 of 6 patients (67%) requiring intraaortic balloon counterpulsation died. Significant complications occurred in 9 of 18 survivors (50%). All operative survivors improved at least 1 New York Heart Association class, with a mean classification improvement of 3.7 to 1.6 (p less than 0.0001); 13 of 16 long-term survivors were in class I or II. Actuarial survival at 1 and 2 years is 94% and 82%, respectively. CABG can be performed electively in octogenarian patients with increased but acceptable mortality and morbidity risks. Functional improvement and long-term survival are excellent.

Aged↗
PubMed1987

Primary repair of traumatic aortic disruption.

From 1979 to 1985, 22 patients (18 male) underwent repair of acute traumatic rupture of the aorta. Ages ranged from 15 to 75 years (mean, 35 years). All patients sustained deceleration injuries in automobile accidents. The majority had injuries to multiple systems and evidence of mediastinal widening on routine chest roentgenograms. Aortography confirmed transection in the descending thoracic aorta near the ligamentum arteriosum in 20. Primary repair was achieved in 15 patients; it was performed in the last 10 consecutive patients. Seven patients had repair with a prosthetic graft. Survival was 82%. Postoperative morbidity usually was related to associated injuries. Primary repair of aortic transection can be accomplished in most patients without the use of prosthetic material.

Accidents, Traffic↗
PubMed1987

Diltiazem as an adjunct to cold blood potassium cardioplegia: a clinical assessment of dose and prospective randomization.

Diltiazem was evaluated as an adjunct to cold blood potassium cardioplegia in 63 patients undergoing elective coronary artery bypass grafting. The dual-phase study compared incrementally increasing doses (50, 100, and 150 micrograms/kg) of diltiazem using a single-blind, randomized schedule with an equivalent volume of placebo added to each of three infusions of cold (10 degrees C +/- 2 degrees C) blood containing potassium chloride at 25 mEq/L for the initial infusion (400 ml) and at 12 mEq/L for the next two infusions (300 ml each). Observations included a number of operative variables, creatine kinase (CK)-MB curves, two-dimensional echocardiography, and pulsed Doppler sonography before operation and on postoperative days 1 and 5. Pulmonary artery thermistor catheter responses were observed for 16 hours postoperatively, as were left ventricular micromanometer-tipped catheter responses in 7 patients. As the dose of diltiazem was increased, there was increasing time to atrioventricular node refunction (23.6 to 62.0 minutes). Diltiazem at 100 micrograms/kg (D-100) resulted in a significantly lower peak CK-MB activity than its placebo. Peak - dp/dt increased in treated patients and decreased in patients given the placebo. The cardiac index in D-100 patients was greater on the first postoperative day than preoperatively. The stroke index returned to the control level by the fifth postoperative day in D-50 and D-100 patients only, and it remained depressed in placebo patients. Although few benefits were realized from the addition of diltiazem to cold blood potassium cardioplegia, there was dose-related prolongation of the atrioventricular node recovery time, which required cardiac pacing and thus was associated with its attendant risks.

Coronary Artery Bypass↗
PubMed1986

A noncannulating coronary perfusion cannula.

A noncannulating cannula was devised to avoid trauma to the coronary ostia and secondary ostial stenosis. The cannula achieves a seal with the aortic wall through the use of bulbous silicone gel-filled tip. The same cannula has effectively perfused the right and left ostia and previously placed aorta-coronary bypass grafts with one exception, in which calcification of the aortic wall prevented a satisfactory seal.

Aortic Valve↗
PubMed1985

The importance of biventricular failure in patients with postoperative cardiogenic shock.

To evaluate the importance of severe biventricular failure in patients with postcardiotomy ventricular failure, we analyzed the data from 30 patients treated with ventricular assist devices (VADs) over a five-year period. All patients had profound postoperative ventricular failure refractory to drugs and an intraaortic balloon (IAB). Evaluation of preoperative ventricular function did not allow prediction of which patients would require VADs. However, the development of perioperative myocardial infarction was an important determinant of the need for postoperative support with a VAD. Twenty patients received only a left VAD (LVAD). Four of them had isolated left ventricular failure; 3 were weaned, and 2 survived. None of the 16 patients with biventricular failure who received only an LVAD were weaned. Ten other patients with biventricular failure received biventricular support, either with a right VAD and IAB, or with two VADs. Of these 10 patients, 5 were weaned and 3 survived. Considering all 26 patients with biventricular failure, those receiving biventricular mechanical support (10) had a better chance (p less than 0.025) of being weaned (5/10) and surviving (3/10) than those who received only an LVAD (0/16). We conclude that biventricular failure is common in patients with postcardiotomy ventricular failure and is often the result of perioperative infarction. While patients with isolated left ventricular failure did well with an LVAD only, those with biventricular failure required biventricular mechanical support for survival.

Adolescent↗
PubMed1985

Intraoperative myocardial protection: a comparison of blood and asanguineous cardioplegia.

Cardiac arrest was achieved in 84 patients using asanguineous cardioplegia and in 97 patients using cold blood potassium cardioplegia. The patient groups were similar in age, sex ratio, and preoperative risk factors. Other than the cardioplegic solution used, the conduct of each operation was identical. There were no differences in mean total pump time (118 minutes for the asanguineous cardioplegia group versus 117 minutes for the cold blood cardioplegia group) or cross-clamp time (73.5 versus 70 minutes, respectively). However, the blood cardioplegia group had a greater number of distal anastomoses per patient (3.9 versus 3.7; p less than 0.05). Myocardial protection was assessed clinically and by serial electrocardiograms. Cellular integrity was determined by release of the myocardial isoenzyme of serum creatine kinase (CK-MB). Cellular morphology was studied in 6 randomly selected patients in each group by electron microscopic examination of left ventricular myocardial samples obtained before and after bypass. Three patients given blood cardioplegia and 5 given asanguineous cardioplegia required intraaortic balloon counterpulsation at termination of bypass. There were no ultrastructural changes in either group. Electrocardiographic changes (Minnesota code) occurred in 12 of 84 patients receiving asanguineous cardioplegia versus 12 of 97 patients receiving cold blood potassium cardioplegia. To maintain a satisfactory cardiac index (greater than 2.0 L/min/m2), 38 of 84 patients given asanguineous cardioplegia versus 25 of 97 patients given blood cardioplegia required inotropic support up to 24 hours postoperatively (p less than 0.05). Infarct size determined from CK-MB release was significantly greater (p less than 0.05) in patients given asanguineous cardioplegia (36.27 gm-equivalents) than in those given blood cardioplegia (26.7 gm-equivalents).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Transfusion↗
PubMed1985

Twelve-year experience with internal mammary artery for coronary artery bypass.

From Feb. 1, 1972, to Jan. 30, 1984, 1,000 patients had isolated coronary bypass with at least one internal mammary artery, and 103 of them had bilateral internal mammary artery grafts. There were 1,395 associated vein grafts and 1,158 internal mammary artery anastomoses, for a total of 2,556 grafts (2.5 per patient). Patients were followed up for 1 to 12 years (mean 6.3 years) and 77 patients were lost to follow-up at a mean of 4.0 years. Operative mortality was 1.4%, with 11 of 14 deaths in the first 240 patients (4.6%) and eight of 14 in the 103 patients with bilateral internal mammary artery grafts. There were 93 late deaths, with an actuarial survival rate of 93% at 5 years and 84% at 10 years. Angina occurred at a mean rate of 6.2% +/- 1.2% per year. Perioperative infarction was detected in 37 patients (3.7%). Late infarction occurred in 75 patients, for a mean rate of 1.5% +/- 0.3% per year. Reoperation (or percutaneous transluminal coronary angioplasty) was necessary in 35 patients, for a mean rate of 0.85% +/- 0.28% per year. Graft patency was assessed by 1,029 follow-up catheterizations in 519 patients. The patency rate of the left internal mammary artery was 96.4% at 1 year, 88.1% at 5 years, and 88.1% at 10 years. That of the right internal mammary artery was 92.8% (p = NS) at 1 year, 84.6% (p = NS) at 5 years, and at 10 years the numbers were too small to be meaningful. Comparison of patency rates for all internal mammary artery grafts with vein grafts gave 1 year graft patency rates of 95.7% versus 93.4% (p less than 0.025), 5 year rates of 87.9% versus 74.0% (p less than 0.001), and 10 year rates of 83.0% versus 41.0% (p less than 0.001). Included in these patency data are 20 free internal mammary artery grafts; 16 were studied (mean 2.3 years) and 12 of these 16 (75%) were patent. Of the 58 sequential internal mammary artery grafts, 18 were studied by catheterization (mean interval 2.0 years); 35 of 36 anastomoses were patent and one end-to-side anastomosis was closed. Morbidity and mortality for patients having internal mammary artery grafting are comparable to those of patients having saphenous vein bypass only. The demonstrated superior patency for internal mammary artery grafts supports the routine use of bilateral internal mammary artery grafting.

Actuarial Analysis↗