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Biomedical subjects

T K Kaul

Publications and source records attributed to T K Kaul.

At least 19 recordsLinked to original sources

Coronary artery bypass grafting in patients with an ejection fraction of twenty percent or less.

Over a 7-year period, 5.8% (n = 210) of patients who underwent coronary artery bypass grafting at our institution had severely impaired global left ventricular function with an ejection fraction of 20% or less. Mean age at operation was 66 years (+/- 0.7; standard error), and 76% of patients were male. Primary indications for operation were unstable angina (73 patients, 35%), return of symptoms with previous bypass grafting (41 patients, 20%), congestive heart failure with reversible ischemia (55 patients, 26%), and recurrent ventricular arrhythmias (41 patients, 20%). Overall, actuarial survival (n = 210) was 82%, 79%, and 73% at 1, 2, and 5 years. Risk of death was highest early after the operation, and then declined rapidly to a constant level. Patients who did not receive retrograde coronary sinus cardioplegia (p = 0.05), older patients (p = 0.004), and those with preoperative ventricular arrhythmias (p = 0.003) or renal failure (p < 0.0001) had an increased risk of death early after operation. Patients with congestive symptoms and those requiring extensive or redo bypass grafting (p = 0.02) were found to be at an increased risk of death throughout the follow-up period. When the number of distal anastomoses performed increased, survival was found to decrease (p < 0.003), and to a greater extent in women than in men (p = 0.02). Of the four primary indications for operation, unstable angina yielded the highest risk-adjusted survival. Successful results after surgical revascularization in patients with severe impairment of ventricular function can be achieved by careful patient selection and management.

Aged

Coronary artery bypass grafting within 30 days of an acute myocardial infarction.

Risks and benefits of performing coronary artery bypass grafting (CABG) within 30 days of an acute myocardial infarction (AMI) were examined. In 642 patients operated on between January 1988 and December 1993, emergent CABG was performed in 46 patients for cardiogenic shock mainly for failed thrombolysis in patients with an evolving AMI. The remaining patients underwent urgent (< 72 hours) or elective (> 72 hours) revascularization for failed percutaneous transluminal coronary angioplasty (n = 73), postinfarction angina (n = 381), vein graft stenosis (n = 100), and complications after an AMI (n = 42). In patients who underwent primary CABG for an uncomplicated AMI, the infarct was subendocardial in 68, anterolateral or septal in 200, inferior or posteroinferior in 200, and posterolateral in 32 patients. Early mortality (< 30 days) was 5.9% for the entire series and 0%, 4.5%, 4.5%, 29%, 9%, 8%, 10%, and 26% for the subsets of patients with subendocardial infarct, anterolateral or septal infarct, inferior or posteroinferior infarct, ischemic mitral regurgitation, left ventricular aneurysm, redo CABG, age more than 70 years, and left ventricular ejection fraction less than 0.30, respectively. By multivariate analysis, independent predictors of early mortality were left ventricular ejection fraction less than 0.30, age more than 70 years, and cardiogenic shock.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Reoperative coronary artery bypass surgery: early and late results and management in 1300 patients.

In this retrospective series overall results after reoperative coronary artery bypass surgery and the subsequent management of recurrent ischemic heart disease in these patients were reviewed. Between September 1980 and September 1993, 17% (n = 1300) of our patients (Pts) undergoing myocardial revascularization (CABG) were reoperative. Of these, 75% were male and 17% were > or = 70 years. One or both internal thoracic arteries (ITA) were used in 25% Pts; a saphenous vein graft (SVG) was used sequentially in 67% or as a separate conduit in 8%. Hospital mortality was higher after redo CABG than after primary CABG (6.9% vs 2.1%, p < 0.0001) and also in Pts receiving SVG rather than IMA as a conduit (7% vs 3.8%, p < 0.001), and in Pts receiving retrograde coronary sinus cardioplegia (RCSC) (n = 504) as compared to those who received antigrade cardioplegia since 1989 (n = 334) (2.5 vs 5.4%, p < 0.05). Throughout the series, independent predictors of hospital mortality by multivariate analysis were: female gender, postoperative myocardial infarction, congestive cardiac failure and stroke. Actuarial survival at 10 years for the patients receiving ITA as a conduit was 86% and for the patients receiving SVG only 76% (p < 0.02); for patients > 70 years was 66% and for patients < 70 years 80% (p < 0.005). Pts with a LVEF < 20% had a poor survival after 2 years. At 10 years cardiac related event free survival after 1st reoperation was 53%. During 13 years 94 Pts underwent subsequent reoperations and 125 Pts underwent saphenous vein graft angioplasty (PTCA), for recurrent ischemic heart disease. Cardiac event free survival at 6 years was clearly superior after multiple reoperative surgery than after graft angioplasty (45% vs 35% p < 0.05). In conclusion, in this series, use of the ITA as a conduit and RCSC has significantly improved Pts survival after redo CABG. Survival and quality of life were further improved in patients requiring multiple reop CABG or graft PTCA.

Age Factors

Cardiac operations in patients with end-stage renal disease.

Factors influencing the survival of 35 consecutive patients in end-stage renal disease who required 40 open heart surgical procedures over the past 8 years were studied. The mean age in these patients was 57.7 +/- 3 years (range, 32 to 77 years); 74.3% of the patients were male; and the average duration of hemodialysis was 3.6 +/- 0.6 years. Twenty-nine myocardial procedures (20 of 29 for unstable angina), six valve replacements, and five combined procedures were performed. The actuarial survivals at 1 and 3 months, and at 1, 5, and 8 years were 90%, 85%, 76%, 55%, and 43%, respectively. Based on the results of univariate analysis, the most significant predictor of both early and late mortality was New York Heart Association (NYHA) class IV congestive heart failure. The 5-year survival in the patients 60 years and older was less favorable than that in patients younger than 60 years (45% versus 63%) (p < 0.05). The 5-year survival in the patients in NYHA class IV was only 27%, as compared to 63% in the patients in class II or III (p < 0.001). All survivors have remained free of angina and 19 of the 21 survivors showed an improvement in their NYHA class. Four patients under 40 years of age have subsequently been able to undergo renal transplantation. Overall, these results justify proceeding with an open heart surgical procedure in dialysis patients, when needed, but before the onset of congestive heart failure.

Adult

Angioplasty versus coronary artery bypass in octogenarians.

We retrospectively analyzed early and late results for two treatment strategies of significant coronary artery disease in 310 octogenarians seen in the last 10 years. One hundred five patients 80 or more years of age had percutaneous transluminal coronary angioplasty (PTCA) and 205 had coronary artery bypass grafting (CABG). The PTCA group differed from the CABG group in having a greater proportion of women (71.4% versus 45.8%; p < 0.001); fewer patients with unstable angina (24.7% versus 33.6%; p < 0.04), acute myocardial infarction (11% versus 23%; p < 0.04), three-vessel coronary artery disease (20% versus 56%; p < 0.0001), and a left ventricular ejection fraction less than or equal to 0.30 (10% versus 21%; p < 0.008); and fewer vessels revascularized (1.2 +/- 0.6 versus 3.5 +/- 0.9; p < 0.0001). Hospital mortality was 8.57% after PTCA (9/14 failed PTCA) and 5.8% after CABG (4/14 emergent, 6/101 urgent, and 2/90 elective). Hospital stay was 7 +/- 0.9 days after PTCA and 14 +/- 1.5 days after CABG (p < 0.01). Independent predictors of hospital mortality obtained by multivariate analysis included failed PTCA and acute myocardial infarction (PTCA group), a left ventricular ejection fraction equal to or less than 0.30, and acute myocardial infarction and emergency CABG (CABG group). Survivors after both CABG and PTCA showed a significant improvement in their New York Heart Association class. Actuarial survival at 5 years after PTCA was 55% and after CABG it was 66% (p < 0.01). Cardiac event-free survival (deaths, myocardial infarction, PTCA, CABG) at 3 years was 61% after PTCA and 81% after CABG (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors

Surgical management in patients with coexistent coronary and cerebrovascular disease. Long-term results.

Between January 1980 and December 1992, 3% (210/6,862) of our patients undergoing myocardial revascularization (CABG) had high grade (> 80%) internal carotid stenosis (CS). One hundred seventy-five of these patients with complete follow up for a minimum of 18 months were studied. Bilateral internal CS was present in 60%, and 75% had other vascular lesions, mainly as peripheral vascular disease (PVD) of the lower limb (50.8%). All patients underwent CAE (carotid endarterectomy) followed by CABG under the same anesthesia. Peripheral vascular lesions, contralateral internal CS and recurrent (n = 43) and progressive vascular lesions (n = 50), were subsequently treated as staged procedures. Hospital mortality was 3.42%. By univariate analysis significant predictors of late mortality were congestive heart failure, COPD, PVD, postoperative myocardial infarction, postoperative stroke, and ischemic cardiomyopathy. Only the latter two were also significant by multivariate analysis. At 12 years, actuarial survival in the presence of these risk factors were 46%, 49%, 22%, 37%, 53%, and 27% respectively. All are significantly lower as compared with the corresponding subsets of patients with the risk factor absent. At 12 years, actuarial survival for the entire series was 65%. Cumulative incidence of postoperative strokes was higher in patients with bilateral internal CS than in patients with unilateral internal CS (p < 0.07) and in patients with neurologic symptoms than asymptomatic patients. At 12 years, actuarial freedom from all cardiac related events, postoperative stroke, and symptomatic PVD were 49%, 82%, and 76% respectively. After successful revascularization these patients should be carefully followed for recurrent and progressive vascular lesions.

Adult

Primary malignant pericardial mesothelioma: a case report and review.

Primary malignant pericardial mesothelioma is a rare tumor of unknown etiology. The prognosis is extremely poor due to generally late presentation, inability to completely eradicate it surgically and its poor response to radiotherapy or chemotherapy. An unusual case of pericardial mesothelioma which presented as constrictive pericarditis is described. A comprehensive review of the 140 cases reported in the literature so far is presented to assist the readers in the management and prognosis of this rare, pathological tumor.

Antineoplastic Combined Chemotherapy Protocols

Mitral valve replacement in patients with severe mitral regurgitation and impaired left ventricular function.

We have studied short- and mid-term effects of preservation and excision of the mitral subvalvar support during mitral valve replacement in 40 patients, who had developed moderate to severe degree of left ventricular function impairment, secondary to pure severe mitral regurgitation. These patients had valve replacement, because valve anatomy was unsuitable for reconstructive procedures. Mitral subvalvar support was excised and valve replaced with a Björk-Shiley prosthesis, in 10 patients with moderately impaired left ventricular ejection fraction (mean 32% +/- 1.2%) and in 18 patients with severely impaired left ventricular function (left ventricular ejection fraction: 22% +/- 0.8%). In 12 patients with severely impaired left ventricular function (left ventricular ejection fraction: 20% +/- 1%) posterior subvalvar apparatus was preserved and valve replaced with a bioprosthesis. Prognosis of patients with moderately impaired left ventricular function was not influenced by the loss of chordopapillary support. Actuarial survival at 8 and 10 years was 46% +/- 7.8% for patients with severely impaired left ventricular function with chordopapillary support excised and 70% +/- 10% for patients with severely impaired left ventricular function with chordopapillary support preserved (p less than 0.01). Preservation of mitral subvalvar support is important in patients with severely impaired left ventricular function (left ventricular ejection fraction less than 25%).

Aged

Functional tricuspid regurgitation following replacement of the mitral valve.

In this series, the effect of replacement of the mitral valve was examined in 86/900 (9.6%) patients who had developed moderate functional tricuspid regurgitation, secondary to rheumatic mitral valvar disease. These patients were subdivided according to the severity of pulmonary hypertension and impairment of right ventricular function. Forty-six patients presented with severe pulmonary hypertension and 40 patients had moderate pulmonary hypertension (mean main pulmonary arterial pressure: 78 +/- 14 mmHg vs 41 +/- 6 mmHg; P less than 0.05). The latter had more advanced disease, greater impairment of right ventricular function and dilatation of the right heart chambers. Functional tricuspid regurgitation regressed in 38/42 survivors with severe pulmonary hypertension and persisted or progressed significantly in 22/34 survivors with impaired right ventricular function despite successful replacement of the mitral valve. The latter underwent replacement of the tricuspid valve (n = 16) or tricuspid annuloplasty (n = 6), at a mean interval of 44 +/- 4.4 months after replacement of the mitral valve, which resulted in 8/22 (23.5%) early deaths. Functional tricuspid regurgitation is more likely to persist in patients with advanced right ventricular failure. Tricuspid valvar competence should be restored in these patients at initial replacement of the mitral valve.

Adult

Tricuspid valve replacement: factors influencing early and late mortality.

Seventy four patients underwent tricuspid valve replacement (TVR), between 1968 and 1983. 93% were female, mean age was 44 +/- 4 years. Tricuspid valve was replaced with a mechanical prosthesis in 52 and a bioprosthesis in 22 patients. Fifty seven patients underwent primary TVR and 17 underwent a secondary TVR following a mean interval of 41 +/- 2 months (SEM) following a previous mitral or tricuspid valve operation. Preoperatively 86% patients were in NYHA class III-IV and congestive cardiac failure (CHF). Early mortality for primary TVR was 36.8% and 35.2% for secondary TVR. Early mortality has been significantly reduced since the introduction of cardioplegic protection for the associated valve lesions. Early mortality was significantly influenced by the reduced preoperative values of FVC and FEV1 in patients with long standing mitral valve disease and by raised preoperative levels of plasma bilirubin and alkaline phosphate in patients with CHF. Risk of thrombotic occlusion and late deaths remained high during the first year after TVR with a mechanical prosthesis.

Adult

Endocrine secreting malignant mediastinal teratoma.

Malignant mediastinal teratoma containing yolk sac elements are rare tumours and invariably have a poor prognosis. An elevated alpha fetoprotein level is a useful indicator of the malignant nature and the invasiveness of the tumour. A case with such a tumour who also presented with precocious puberty is described. This patient was treated with radiotherapy and chemotherapy prior to radical surgical excision, and has now survived for over 64 months without evidence of metastases.

Child

Combined mitral and aortic valve replacement with Bjørk-Shiley prostheses: long term survival and valve-related complications.

Between 1974 and 1985, combined aortic and mitral valve replacement (DVR) was performed in 209 patients using Bjørk-Shiley tilting-disc prostheses. Early and late mortality were 9.5% and 10.5% respectively for the entire series. Factors significantly influencing early mortality were: Emergency DVR, preoperative NYHA Class IV, double valve, critical stenosis, and small aortic replacement prostheses. The effect of the latter was augmented by the suboptimal orientation of the implanted prostheses. The overall survival was 74 +/- 4.4% at 12 years; but was only 40 +/- 6.1% at 8 years in patients who were in NYHA class IV preoperatively. Intermittent disc occlusion (DO) and thrombotic disc occlusion (TO), presented as early, anticoagulant related haemorrhage (AH) and prosthetic valve endocarditis (ENDO) as sporadic, and thromboembolism (TE) and paravalvular leak (PVL) as continuous risk factors. Freedom from all known valve-related complications was 77 +/- 4.5% at 12 years (DO, TO, AH, ENDO, TE, PVL: 98%, 97%, 96%, 96%, 88% and 89% respectively). Lethal DO and TO occurred in mitral prostheses. Freedom from reoperation was 95% at 5 and 12 years. Patient-related valve failure rate in this series is comparable with the other series which used mechanical prostheses and is lower than those which used bioprostheses.

Adult

Vasoactive pressure hormones during and after cardiopulmonary bypass.

The differences in the pattern of the vasoactive hormone release in response to the stress of surgery and cardiopulmonary bypass (CPB) (pulsatile n = 15 and non pulsatile n = 23) were studied in the adult patients with mitral valve disease (MVD), aortic valve disease (AVD), and the coronary artery disease (CAD). A differential stimulation of the osmoreceptors, baroceptors, renin-angiotensin and the sympathetico-adrenal systems in these patients, resulted in the variations in the pattern of hormone release. Patients with MVD showed a greater stimulation of osmoreceptors, baroceptors and release of Arginine vasopressin (AVP). Renin-angiotensin system was more easily triggered in patients with AVD or CAD; and sympathetico-adrenal system in patients with CAD. The renin-angiotensin-aldosterone axis was better preserved in patients with CAD (r = 0.49, p less than 0.001) than in the patients with MVD (r = 0.38, p less than 0.02). Plasma renin release showed a significant correlation with noradrenaline release in the patients with MVD (r = 0.47, p less than 0.01); but this relationship was lost in the patients with the CAD, due to an excessive noradrenaline release. Pulsatile bypass reduced but did not abolish this response. Under unfavourable conditions, the stress response may persist in the early post-operative period.

Aortic Valve

Late results of aortic valve replacement with Bjork Shiley prostheses: a comparison of standard aortic valve prosthesis with reversed mitral valve prosthesis implanted in aortic position.

Between 1976 and 1983, 435 patients underwent aortic valve replacement (AVR) with Bjork Shiley prostheses. Standard aortic Bjork Shiley prostheses (ABP) were used in 150 patients (Group I) and a reversed mitral Bjork Shiley prostheses in 285 (MBP in 250 and MBC in 35) patients (Group II). There was no significant difference in the number of the patients with valve calcification or the size of aortic root in the 2 groups. There was no significant difference in the early mortality in these two groups. The total follow up period in Group I was 912 years and 2130 years in Group II. The incidence of major aseptic prosthetic dehiscence and valve occlusion with tissue ingrowth were higher in Group I than in Group II. Reversed Bjork Shiley mitral valve prosthesis was successfully used in aortic position with reduced incidence of valve related complications.

Aortic Valve

Plasma albumin and calcium levels following cardiopulmonary bypass.

A significant fall in the levels of plasma albumin and a corresponding fall i in the levels of extracellular calcium occurred following cardiopulmonary bypass with the crystalloid prime. Postoperative hypoalbuminaemia was well tolerated, except in the patients with poor left ventricular function. Postoperative hypocalcaemia may increase digoxin sensitivity and may augment the negative inotropic effect of verapamil.

Calcium

Late results of total correction of tetralogy of Fallot in adults.

Between 1966 and 1986, 30 patients underwent total correction of the tetralogy of Fallot. Preoperative presenting features were: dyspnoea on exertion, clubbing, cyanosis and polycythaemia. Twenty-six patients had one or more palliative procedures prior to definitive repair. Preoperatively, all patients had a significant gradient across the right ventricular outflow tract (mean gradient 70 +/- 46 mmHg). Peak right ventricle to left ventricle systolic pressure ratio (pRV/LV) was 0.9 +/- 0.2. A functioning Blalock Taussig shunt was ligated in 11 patients prior to the institution of cardiopulmonary bypass. All patients had a patch closure of the ventricular septal defect. An additional muscle bundle resection from the right ventricular outflow tract was performed in 15, pulmonary valvotomy in 6 and enlargement of the right ventricular outflow tract in 2 patients. There was a significant fall in pRV/LV ratio postoperatively (P less than 0.05). There were 3 early and 2 late deaths. Mild right ventricular outflow tract obstruction has persisted in all survivors. Four patients have remained on antiarrhythmic drugs. Long term results after definitive repair were satisfactory in this group of adult patients who have survived due to palliative procedures performed during childhood.

Adult