Short- and long-term prognosis after coronary artery bypass grafting in relation to smoking habits

A study was conducted to determine the conditions needed to achieve the equilibrium concentration for the epimerization of d-lysergic acid diethylamide (LSD) to iso-LSD. The reaction was followed by integration of the C-9 resonance of LSD and iso-LSD by proton nuclear magnetic resonance (NMR). The C-9 resonance of LSD and iso-LSD appear as singlets at 6.35 and 6.27 ppm respectively. Starting with pure LSD, the conversion to iso-LSD is attained at temperatures above 37 degrees C and pH levels over 7.0. At a pH of 7.0 or higher, the LSD/iso-LSD ratio of 9:1 is achieved after one week at 45 degrees C or two weeks at 37 degrees C. Starting with iso-LSD, the conversion to LSD requires more vigorous conditions. The 9:1 LSD/iso-LSD ratio is attained only after 6 weeks at a temperature of 45 degrees C and a pH of 9.7. At lower pH levels, the reaction proceeds more slowly. The 9:1 LSD/iso-LSD ratio is achieved whether the starting material is LSD or iso-LSD and therefore represents an equilibrium concentration (K = 9). In addition, the more vigorous conditions needed to achieve equilibrium of iso-LSD to LSD demonstrate the difficulty in extraction of the epimerizable proton of iso-LSD. This study is the first to quantitate the epimerization of LSD by NMR techniques and establishes the conditions needed to induce epimerization in solution.     

Projection-based respiratory-resolved left ventricular volume measurements in patients using free-breathing double golden-angle 3D radial acquisition

Objective

To refine a new technique to measure respiratory-resolved left ventricular end-diastolic volume (LVEDV) in mid-inspiration and mid-expiration using a respiratory self-gating technique and demonstrate clinical feasibility in patients.

Materials and methods

Ten consecutive patients were imaged at 1.5 T during 10 min of free breathing using a 3D golden-angle radial trajectory. Two respiratory self-gating signals were extracted and compared: from the k-space center of all acquired spokes, and from a superior–inferior projection spoke repeated every 64 ms. Data were binned into end-diastole and two respiratory phases of 15% respiratory cycle duration in mid-inspiration and mid-expiration. LVED volume and septal–lateral diameter were measured from manual segmentation of the endocardial border.

Results

Respiratory-induced variation in LVED size expressed as mid-inspiration relative to mid-expiration was, for volume, 1 ± 8% with k-space-based self-gating and 8 ± 2% with projection-based self-gating (P = 0.04), and for septal–lateral diameter, 2 ± 2% with k-space-based self-gating and 10 ± 1% with projection-based self-gating (P = 0.002).

Discussion

Measuring respiratory variation in LVED size was possible in clinical patients with projection-based respiratory self-gating, and the measured respiratory variation was consistent with previous studies on healthy volunteers. Projection-based self-gating detected a higher variation in LVED volume and diameter during respiration, compared to k-space-based self-gating.

     

A placebo-controlled study of growth hormone in patients with congestive heart failure

AIM: Experimental data in heart failure models and an open trial of seven patients with idiopathic dilated cardiomyopathy have suggested beneficial effects of growth hormone on cardiac function. The aim of the present study was to evaluate growth hormone effects on cardiac function in a placebo-controlled study. METHODS: Twenty two patients with congestive heart failure of different aetiologies in NYHA II and III and an echocardiographic ejection fraction <0.45 were studied in a 3 month double-blind placebo-controlled study with growth hormone added to optimal heart failure therapy. Patients received either placebo (n=11) or recombinant human growth hormone (n=11) in an initial dose of 0.1 IU x kg(-1) week(-1) for 1 week, and thereafter 0.25 IU x kg(-1) week(-1) for the rest of the treatment period. Cardiac function was assessed by equilibrium radionuclide angiography and Doppler echocardiography. Functional capacity was evaluated by computerized bicycle exercise electrocardiography. RESULTS: Recombinant human growth hormone had no significant effect on systolic or diastolic cardiac function, exercise capacity or neuroendocrine activation. In addition, there was no overall improvement in functional class or dyspnoea grade. Insulin-like growth factor-I significantly increased demonstrating that the growth hormone had an endocrine effect. CONCLUSION: This is the first double-blind and placebo-controlled study of the administration, over 3 months, of recombinant human growth hormone in patients with congestive heart failure of different aetiologies. The treatment was safe and without serious side effects. However, no beneficial effects on cardiac function or structure could be detected.     

Recovery from left ventricular asynergy in ischemic cardiomyopathy following long-term beta blockade treatment

Many environmental pollutants interact with solar near-ultraviolet (nuv) light in a manner which greatly increases their toxic effects. The phenomenon of light-mediated toxicity (phototoxicity) is only now becoming generally recognized to any significant degree. Manufacture of, and loading munitions with, the explosive 2,4,6-trinitrotoluene (TNT) in past decades caused contamination of soils and sediments at levels exceeding 1000 ppm and of waters at levels near saturation (100 ppm). Manufacture of TNT produces numerous nitrated by-products, and most of these compounds, including TNT, can be metabolized by many species, including bacteria, fungi, plants, and mammals. This study investigated the phototoxicity of TNT, and 2,3-, 2,4-, 2,6-, and 3,4-dinitrotoluene (DNT) and -diaminotoluene (DAT), and the major metabolites 2-amino-4,6-dinitrotoluene (2A) and 4-amino-2,6-dinitrotoluene (4A), to Daphnia magna (acute toxicity) and Lytechinus variagatus (sea urchin) embryos (subacute, developmental toxicity). Most of the compounds were weakly toxic or nontoxic in the dark. All were phototoxic to sea urchins. In D. magna, 2,3- and 3,4-DNT/DAT and 4A were not toxic but were phototoxic, and 2A was toxic and phototoxic; the other isomers were not toxic or phototoxic to this species.     

Impact of a history of diabetes mellitus on quality of life after coronary artery bypass grafting

AIM: To describe the improvement in various aspects of quality of life (QoL) after coronary artery bypass grafting (CABG), in relation to a previous history of diabetes mellitus. PATIENTS: All patients from western Sweden who underwent CABG between 1988 and 1991 without simultaneous valve surgery. METHODS: Patients were approached with three questionnaires: The Physical Activity Score, the Nottingham Health Profile and the Psychological General Well-being Index prior to surgery and 3 months, 1 and 2 years thereafter. RESULTS: All three questionnaires already showed a significant improvement in QoL after 3 months, remaining at a similar level 1 and 2 years after the operation. In terms of Physical Activity Score improvement was of similar magnitude in diabetic and non-diabetic patients. In terms of the Psychological General Well-Being Index significant and similar improvements were found in diabetic and non-diabetic patients at each evaluation. In terms of the Nottingham Health Profile there was a significant improvement both in diabetic and non-diabetic patients 3 months, 1 and 2 years after the operation. However, improvement was more marked in diabetic than in non-diabetic patients at each evaluation. CONCLUSION: For 3 months, 1 and 2 years after CABG various aspects of QoL as estimated with three different instruments, improved significantly both in diabetic and in non-diabetic patients compared with the situation prior to the operation. However, the three instruments differed somewhat. Thus, whereas in the Physical Activity Score, diabetic patients tended to improve less markedly than non-diabetic patients, the opposite was found in the Nottingham Health Profile.     

Impact of coronary artery bypass grafting on various aspects of quality of life

OBJECTIVE: To prospectively study the improvement in quality of life (QoL) after coronary artery bypass surgery (CABG). PATIENTS AND METHODS: Consecutive patients (n = 2121) who underwent CABG at Sahlgrenska University Hospital between 1988 and 1991 received 3 questionnaires for the study of QoL: the Physical Activity Score, the Nottingham Health Profile and the Psychological General Well-being Index, which were responded both before surgery and at 3 months (n = 1059), 1 year (n = 1045) and 2 years (n = 1027) postoperatively. RESULTS: All differences were tested against baseline. The Physical Activity Score improved (mean 4.3 before CABG, 3.1, 3 months after (P < 0.0001), and 2.8, 2 years postoperatively (P < 0.0001)). The Nottingham Health Profile score improved (mean 20.5 before CABG, 11.4, 3 months (P < 0.0001), and 10.4, 2 years postoperatively (P < 0.0001)). The Psychological General Well-being Index improved (mean 91.1 before CABG, 103.8, 3 months (P < 0.0001), and 105.8 (P < 0.0001), 2 years after CABG). The subscale analyses of the Nottingham Health Profile and the Psychological General Well-being Index 2 years after CABG showed the greatest improvement in areas reflecting physical capacity and pain, to be followed by mental qualities. At 2 years after CABG only sexual problems were still markedly frequent, and independent predictors for sexual problems after surgery were preoperative problems (P < 0.00001), male sex (P < 0.0001), and diabetes mellitus (P = 0.0008). CONCLUSION: QoL was markedly and significantly improved after CABG. The major improvement was seen already at 3 months, with further slight improvement observed 2 years after surgery. The major improvement was found in areas reflecting physical capacity and pain, which is consistent with symptomatic and objective measurements after CABG. In contrast to the overall improvement in QoL sexual problems were still markedly common 2 years after CABG. The mechanism for this is not fully understood and needs further investigation.     

Early effects of coronary artery bypass surgery and cold cardioplegic ischemia on left ventricular diastolic function: evaluation by computer-assisted transesophageal echocardiography

OBJECTIVE: Although left ventricular (LV) systolic function undergoes a temporary decrease after cardiopulmonary bypass (CPB) in patients undergoing coronary artery bypass grafting (CABG), data on the effects of CABG and cardioplegic arrest on LV diastolic function are contradictory. The objective of the present study was to further evaluate the effects of CABG and CPB on LV diastolic function. DESIGN: A prospective study. SETTING: A multi-institutional investigation at a university hospital. PARTICIPANTS: 20 patients on beta-receptor antagonists, scheduled for CABG and with a preoperative ejection fraction over 0.5. INTERVENTIONS: Central hemodynamic measurements, transesophageal LV short-axis images, and mitral Doppler flow profiles were obtained before and after volume loading that in turn was performed both before surgical incision and after weaning from CPB. MEASUREMENTS AND MAIN RESULTS: Heart rate, cardiac output, and peak atrial filling velocity increased; systemic vascular resistance decreased; whereas stroke volume, LV area ejection fraction, deceleration rate and slope of early diastolic filling, time-velocity integral of early diastolic filling, and the ratio between early and atrial peak filling velocity were unchanged post-CPB compared with pre-CPB. LV end-diastolic stiffness that was calculated for each patient pre-CPB and post-CPB using the formula: P = B*eS*A), where P is the LV filling pressure and A is the end-diastolic short-axis area, was unchanged post-CPB compared with pre-CPB. CONCLUSIONS: Both the active and passive components of LV diastolic function are well maintained shortly after CABG and cardioplegic arrest in patients with a good preoperative systolic LV function.     

Study and treatment of heart failure require new approaches. Natriuretic peptides can be safe and simple diagnostic and outcome measures

Analysis of plasma natriuretic peptides and related propeptide fragments may be a cost-effective aid to diagnostic evaluation and treatment follow-up in cases of heart failure. In diagnostic potential such variables may constitute first-line measures of high negative predictive value, allowing further examination, e.g. by echocardiography, in cases where values are above the respective cut-off levels. However, in many cases evaluation of published reports is rendered difficult by their omission of information on such pre-analytical variables as blood sampling and storage, and drug therapy. Moreover, different analytical methods may yield widely divergent results. Thus, before such assays are introduced in general use, their long-term validity needs to be ensured, for instance by consistency in calibration, and measurements need to be made in representative series of unselected patients for the determination of appropriate cut-off levels.     

Long-term Doppler echocardiographic results of aortic or mitral valve replacement with Biocor porcine bioprosthesis

OBJECTIVES: Our objectives were to evaluate the long-term bioprosthetic and cardiac functional outcome after insertion (over a 10-year period) of a new-generation porcine zero pressure-fixed Biocor bioprosthesis, as well as to determine the echocardiographic accuracy for selection of patients requiring reoperation. The long-term systematic Doppler echocardiographic assessment after valve replacement with this bioprosthesis is lacking. METHODS: Between January 1983 and January 1993, we inserted 756 Biocor prostheses in the aortic (619) or mitral (137) positions. All 51 patients who had a reoperation during the follow-up time were evaluated echocardiographically before reoperation. Additionally, 263 of 446 patients (59%) with aortic bioprostheses and 42 of 74 patients (57%) with mitral bioprostheses who were alive in January 1993 had long-term echocardiographic follow-up. RESULTS: Group A: Normally functioning bioprostheses were found in the aortic position in 242 of 263 patients and in the mitral position in 33 of 42 patients. Group B: Thirty patients had abnormal bioprosthetic function. Eleven patients had regurgitation, 3 had a combined lesion, and signs of calcification appeared in 16 patients with aortic valves, all with a peak gradient of above 60 mm Hg. Group C: Patients who had a reoperation (41 aortic and 10 mitral) within the follow-up period were followed up echocardiographically from the detection of a possible valve dysfunction until reoperation, and the findings accorded well with those at operation in 49 of 51 patients. CONCLUSIONS: These findings suggest that, during a long-term follow-up, most bioprostheses function normally, facilitating improved heart function. Abnormalities in a bioprosthesis usually develop gradually, enabling their detection by Doppler echocardiographic evaluations performed regularly or in case of any symptomatic deterioration.     

Improvement in quality of life during 5 years after coronary artery bypass grafting

OBJECTIVE: To describe the changes in various aspects of quality of life (QOL) from before coronary artery bypass grafting (CABG) to 5 years after the procedure. PATIENTS AND METHODS: Patients who underwent CABG in the western region of Sweden in 1988-1991 were approached with questionnaires evaluating their QOL prior to and 3 months and 1, 2, and 5 years after the operation. Three different instruments were used: the Nottingham Health Profile, the Psychological General Well-Being Index, and the Physical Activity Score. RESULTS: In all 2121 patients underwent CABG, of whom 310 died during 5 years of follow-up. With all three instruments QOL had improved 5 years after CABG compared with prior to the operation. However, all three instruments revealed a slight but significant deterioration in estimated QOL between 2 and 5 years after CABG. CONCLUSIONS: QOL 5 years after CABG is better than that prior to the operation, but between 2 and 5 years after the operation a slight deterioration in QOL is observed.