Effects of exercise-based cardiac rehabilitation in patients with acute coronary syndrome aged 80 years and older

Background

The beneficial effects of exercise-based cardiac rehabilitation (exCR) in patients with acute coronary syndromes (ACS) are well known. Patients aged 80+ have, however, been underrepresented in randomized controlled trials.

Purpose

The primary aim was to evaluate effects of exCR in patients with ACS 80+ in terms of maximum aerobic capacity, compared with a control group. Secondary aims were to evaluate effects of exCR between groups regarding muscular endurance, submaximal aerobic capacity, physical function and self-reported health.

Methods

A total of 26 patients (58% men), with ACS, median age 82.5 (25th-75th percentiles, 81–84) years, were included at a university hospital. Patients were randomized to hospital-based exCR, including aerobic, resistance- and balance exercises 2 times/week and a home-based exercise program 1 time/week or to a control group (C-group) for 4 months. We report differences in changes (0–4 months) between the groups regarding maximum aerobic capacity (exercise ECG), 6MWT, muscle endurance tests (shoulder flexion and heel-lifts), timed-up and go (TUG), Short Physical Performance Battery (SPPB), one leg stand test and self-reported health (one item question). T-tests, Mann-Whitney U tests and Chi2-tests were used as appropriate to describe differences between groups.

Results

There were no significant differences between groups at baseline, except for age with the exCR-group being older. At 4 months, we found no significant differences between the groups in maximum aerobic capacity. However, the exCR-group significantly improved their 6-min walking distance more, with a median of 39 m (17–57.5), compared to 16.5 m (−15.5–33) in the C-group, p=0.04. In addition, the exCR-group significantly improved in muscle endurance (maximum reps) while the C-group declined; heel-lift right, mean 2.3±3.8 vs −1.6±4.5, p=0.04 and left, mean 2.9±3.9 vs −4.6±4.6, p=0.001, shoulder flexion mean 5.5±4.5 vs −3.1±3.1, p≤0.001. Moreover, the exCR-group significantly improved their physical function in terms of SPPB total score with in median 1.5 (1–2) points, compared to 0 (−1–1) in the C-group, p=0.02 and one leg stand test 1.5 (0–2) points, compared to a decline with −0.5 (−2–0) points in the C-group, p<0.001. There were no significant differences between groups in shoulder abduction, TUG and self-reported health.

Conclusions

We report introductory results that patients with ACS, aged 80+, participating in an exCR program can improve walking distance, muscle endurance and physical function, however not maximum aerobic capacity. Therefore, we encourage an increased referral to exCR of this increasing group of patients to potentially enable more elderly to preserve mobility and independence in their daily living. These results must, however, be confirmed in larger studies.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Swedish Heart- and Lung Association

Radiosensitivity: Gender and Order of Administration of G-CSF, An Experimental Study in Mice

To elucidate the potential influence of stimulating bone marrow before cell-cycle-dependent irradiation, we sought to determine overall survival in mice receiving total-body irradiation (TBI) when administered granulocyte stimulating factor (G-CSF) at different time points. Gender differences were also studied. C57/BL/6J mice, aged 9-14 weeks, received 8 Gy TBI in a perspex cage using a linear accelerator. In each of five different experiments, three groups were studied: 1. one control group receiving TBI only; 2. one group treated with filgrastim [500 lg/kg subcutaneously/intraperitoneally (s.c./i.p.)] the day before TBI, followed by daily filgrastim injections postirradiation (1-5 days); and 3. one group treated with daily filgrastim injections only post-TBI (1-5 days). Each experimental group included male and female mice. Survival of the mice was monitored daily, and mice were euthanized when their condition deteriorated. A total of 293 mice were monitored for at least 37 days post-TBI. Control mice that received 8 Gy TBI showed a significant gender difference, with a median survival of 22 days in females and 17 days in males. Addition of G-CSF, irrespective of pre- or postirradiation, significantly improved survival, but in males the improvement was significantly better when G-CSF was not given before TBI. Improved survival in females was independent of the order of administration of GCSF. Multiple filgrastim injections were more effective than a single injection, and s.c. administration was not better than i.p. In conclusion, these findings indicate that male mice are more sensitive to TBI than females. Filgrastim improved survival in both genders irrespective of whether given pre- or postirradiation, but in males the improvement was significantly less if an injection was given before irradiation. These results suggest that, to prevent toxicity most effectively, GCSF should not be given before cytotoxic therapy. While a completely different experimental model was used here, these results may also be extrapolated to indicate that endocrine cell-cycle suppression therapy should not be given before or during cytotoxic therapy of hormone-dependent tumors (e.g., breast and prostate cancer), thus a reduction in the efficacy of cell-cycle-dependent therapy can be prevented.

Survival and neurological outcome in the elderly after in-hospital cardiac arrest

BACKGROUND

There have been few studies of the outcome in elderly patients who have suffered in-hospital cardiac arrest (IHCA) and the association between cardiac arrest characteristics and survival.

AIM

The aim of this large observational study was to investigate the survival and neurological outcome in the elderly after IHCA, and to identify which factors were associated with survival.

METHODS

We investigated elderly IHCA patients (≥70years of age) who were registered in the Swedish Cardiopulmonary Resuscitation Registry 2007-2015. For descriptive purposes, the patients were grouped according to age (70-79, 80-89, and ≥90years). Predictors of 30-day survival were identified using multivariable analysis.

RESULTS

Altogether, 11,396 patients were included in the study. Thirty-day survival was 28% for patients aged 70-79 years, 20% for patients aged 80-89 years, and 14% for patients aged ≥90years. Factors associated with higher survival were: patients with an initially shockable rhythm, IHCA at an ECG-monitored location, IHCA was witnessed, IHCA during daytime (8 a.m.-8 p.m.), and an etiology of arrhythmia. A lower survival was associated with a history of heart failure, respiratory insufficiency, renal dysfunction and with an etiology of acute pulmonary oedema. Patients over 90 years of age with VF/VT as initial rhythm had a 41% survival rate. We found a trend indicating a less aggressive care with increasing age during cardiac arrest (fewer intubations, and less use of adrenalin and anti-arrhythmic drugs) but there was no association between age and delay in starting cardiopulmonary resuscitation (CPR). In survivors, there was no significant association between age and a favourable neurological outcome (CPC score: 1-2) (92%, 93%, and 88% in the three age groups, respectively).

CONCLUSIONS

Increasing age among the elderly is associated with a lower 30-day survival after IHCA. Less aggressive treatment and a worse risk profile might contribute to these findings. Relatively high survival rates among certain subgroups suggest that discussions about advanced directives should be individualized. Most survivors have good neurological outcome, even patients over 90 years of age.

Long-term major adverse cardiovascular events and quality of life after coronary angiography in elderly patients with acute coronary syndrome

BACKGROUND

Although the elderly comprise the majority of acute coronary syndrome (ACS) patients, limited data exist on major adverse cardiovascular events (MACEs) and quality of life (QoL).

OBJECTIVES

To study MACEs and QoL prospectively in ACS patients >70years referred for coronary angiography.

METHODS

A prospective observational study that included ACS patients >70years undergoing coronary angiography. The outcomes were MACEs and QoL 3years after inclusion. MACEs were defined as death, recurrent ACS, new-onset of heart failure and repeated revascularization by coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). A QoL questionnaire was completed by the patients along with a physical examination and a personal interview at the 3-year follow-up. Multivariate analysis was performed to identify the predictors for MACEs.

RESULTS

In total, 138 patients (mean age 78.8±3.8years) with ACS were included in the study. Mean follow-up was 1196±296days. In all, 42% of the patients had MACEs and 25% had post-ACS heart failure. The mortality rate was 11%. After adjusting for significant cardiovascular risk factors, the following factors were significantly associated with MACEs: Age, high-sensitive troponin T (hsTNT), use of diuretics and reduced left ventricular ejection fraction (LVEF). Furthermore, the QoL evaluated with SF-36 in survivors from ACS at the end of study was similar to the QoL in an age-matched healthy Swedish population.

CONCLUSIONS

In this prospective study on elderly ACS patients MACEs still occurred in 42% of the cases (despite low mortality and good QoL), with post-ACS heart failure as the most important event.

No clear effect of postoperative radiotherapy on survival of breast cancer patients with one to three positive nodes: a population-based study

BACKGROUND

In published radiotherapy trials, the failure rate in the control arm among patients with one to three positive nodes is high compared with that seen with modern adjuvant treatments. Therefore, the generalizability of the results has been questioned. The aim of the present study was to compare relative survival in breast cancer patients between two Swedish regions with screening mammography programs and adjuvant treatment guidelines similar with the exception of the indication of radiotherapy for patients with one to three positive nodes.

PATIENTS AND METHODS

Between 1989 and 2006, breast cancer patients were managed very similarly in the west and southeast regions, except for indication for postoperative radiotherapy. In patients with one to three positive nodes, postmastectomy radiotherapy was generally given in the southeast region (89% of all cases) and generally not given in the west region (15% of all cases). For patients with one to three positive nodes who underwent breast-conserving surgery, patients in the west region had breast radiotherapy only, while patients in the southeast region had both breast and lymph nodes irradiated.

RESULTS

The 10-year relative survival for patients with one to three positive lymph nodes was 78% in the west region and 77% in the southeast region (P = 0.12). Separate analyses depending on type of surgery, as well as number of examined nodes, also revealed similar relative survival.

CONCLUSION

Locoregional postoperative radiotherapy has well-known side-effects, but in this population-based study, there was little or no influence of this type of radiotherapy on survival when one to three lymph nodes were involved.

Effects of ex vivo platelet supplementation on platelet aggregability in blood samples from patients treated with acetylsalicylic acid, clopidogrel, or ticagrelor

BACKGROUND

Transfusion of platelet concentrate is often used to treat bleeding in patients on platelet inhibitors, but little is known about its efficacy between different inhibitors. We assessed the effect of ex vivo platelet supplementation on platelet aggregability in blood samples from patients treated with acetylsalicylic acid (ASA), clopidogrel, or ticagrelor.

METHODS

Platelet aggregability was investigated with multiple electrode aggregometry with adenosine diphosphate (ADP), arachidonic acid (to assess ASA-dependent aggregability), and thrombin receptor activating peptide-6 (TRAP) as activators in whole-blood samples from patients treated with ASA (n=10), ASA+clopidogrel (n=15), or ASA+ticagrelor (n=15), and from healthy controls (n=10). Aggregability was measured before and after supplementation of AB0-compatible fresh apheresis platelets (+46, +92, and +138×10(9) litre(-1)).

RESULTS

Both ASA-dependent and ADP-dependent aggregability improved in a dose-dependent fashion after platelet supplementation. ASA-dependent aggregability was completely restored in all patient groups, but there was only a small improvement in ADP-dependent aggregability in patients on dual antiplatelet therapy. There was less effect of platelet supplementation on ADP- and ASA-dependent aggregability in ticagrelor-treated patients than in clopidogrel-treated patients [3.9 (95% confidence interval 1.6-6.3) vs 9.0 (5.2-12.8) AU×min (P=0.021) and 48 (36-59) vs 69 (60-78) AU×min (P=0.004), respectively, at the highest platelet dose].

CONCLUSIONS

Platelet supplementation improved platelet aggregability independently of antiplatelet therapy. The effect on ADP-dependent platelet inhibition was limited however. Reduced effect of platelet transfusion is more likely within 2 h of drug intake in patients treated with ASA+ticagrelor compared with ASA+clopidogrel.

Quantification of activity by alpha-camera imaging and small-scale dosimetry within ovarian carcinoma micrometastases treated with targeted alpha therapy

Targeted alpha therapy (TAT) a promising treatment for small, residual, and micrometastatic diseases has questionable efficacy against malignant lesions larger than the α-particle range, and likely requires favorable intratumoral activity distribution. Here, we characterized and quantified the activity distribution of an alpha-particle emitter radiolabelled antibody within >100-µm micrometastases in a murine ovarian carcinoma model. Nude mice bearing ovarian micrometastases were injected intra-peritoneally with 211At-MX35 (total injected activity 6 MBq, specific activity 650 MBq/mg). Animals were sacrificed at several time points, and peritoneal samples were excised and prepared for alpha-camera imaging. Spatial and temporal activity distributions within micrometastases were derived and used for small-scale dosimetry. We observed two activity distribution patterns: uniform distribution and high stable uptake (>100% IA/g at all time points) in micrometastases with no visible stromal compartment, and radial distribution (high activity on the edge and poor uptake in the core) in tumor cell lobules surrounded by fibroblasts. Activity distributions over time were characterized by a peak (140% IA/g at 4 h) in the outer tumor layer and a sharp drop beyond a depth of 50 µm. Small-scale dosimetry was performed on a multi-cellular micrometastasis model, using time-integrated activities derived from the experimental data. With injected activity of 400 kBq, tumors exhibiting uniform activity distribution received <25 Gy (EUD=13 Gy), whereas tumors presenting radial activity distribution received mean absorbed doses of <8 Gy (EUD=5 Gy). These results provide new insight into important aspects of TAT, and may explain why micrometastases >100 µm might not be effectively treated by the examined regimen.

Differential locomotion of long- and short-term IL-2-activated murine natural killer cells in a model matrix environment

Tumour infiltration by activated natural killer (A-NK) cells is a pre-requisite for tumour eradication by adoptive NK cell transfer. Extravasated A-NK cells do not always succeed in reaching the crucial target cell conjugation. Therefore, we wished to study A-NK cell locomotion and interactions with melanoma cells in a matrix environment (Matrigel) by electron, confocal and fluorescence microscopy. Two distinct patterns of A-NK cell-mediated matrix disintegration were revealed during incubation of tumour cells and A-NK cells in Matrigel: (1) A-NK cells pre-cultured for 5 days altered the homogeneous texture of the Matrigel, an initial microporous appearance became a loose filamentous meshwork by 24 h. Matrix degrading protease inhibitors could not fully prevent this, but could delay the process; and (2) A-NK cells pre-cultured for 6 days or more, instead formed large excavations in the Matrigel leaving the remaining matrix less affected compared to the effects by the younger A-NK cells. By histochemical staining with Cupromeronic Blue, the excavations were shown to contain proteoglycan material. Protease inhibitors had no discernable effect on the development of the excavations. The conspicuous capacity of A-NK cells to disintegrate extracellular matrix and the formation of large excavations seems only partially to depend on matrix-degrading proteases. Formation of extracellular proteoglycan material is suggested to facilitate A-NK cell locomotion within a matrix environment.

Delayed start of adjuvant 5-FU/leucovorin based chemotherapy in colon cancer is safe up to 12 weeks postoperatively

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Background: Postoperatively adjuvant chemotherapy with 5-Fluorouracil modulated by leucovorin alone or in combination with Oxaliplatin significantly reduce the risk of recurrence and prolong the disease free survival (DFS) in patients with a radical resection for colonic carcinoma. In all reported studies the chemotherapy has started within 6–8 weeks after surgery. Due to complications following surgery it is not always possible to start adjuvant chemotherapy within this time frame. The aim of the present retrospective study was to investigate the effect on risk of recurrence and effect on DFS in patients treated in clinical routine practice in one single institution. Methods: Between 1992 and 2004, 234 patients (121 females, 113 males) with a median age of 66 years (range 25–84 years) received weekly bolus 5-FU/leucovorin postoperatively for 6 months. 211 (90.2%) had a Dukes′ C tumour and 23 (9.8%) high risk Dukes′ B tumour. The median time from surgery and start of adjuvant therapy was 71 days (range 30–190 days). Patients were divided in three groups, where chemotherapy started within 6 weeks, 8 weeks and 12 weeks after surgery and the frequency of recurrent disease and DFS were compared between these groups. Results: Medium follow-up was 35.6 months (range 2,7- 140.6 months). Five patients (21.7%) with Dukes′ B tumours and 76 patients (36.0%) with Dukes′ C tumours recurred during the follow-up period. There were no differences in the proportion of Dukes′ B and C tumours between the three groups. Recurrent disease was more frequent but no significant difference in patients that started within 6 weeks (52.6%) compared with patients that started within 8 weeks (45.5%) and 12 weeks (35.5%). In all three groups there was a tendency to better DFS in patients that started later than 6 or 8 weeks, but these differences were not significant. Conclusions: Starting adjuvant 5-Fluorouracil/leucovorin alone later than 6–8 weeks do not negatively effect the risk of recurrent disease or DFS.

No significant financial relationships to disclose.

High dose-rate brachytherapy of prostate cancer utilising Iridium-192 after-loading technique: technical and methodological aspects

The aim of this study was to focus on certain characteristic problems associated with Iridium-192 high dose-rate brachytherapy (Ir-192 HDR-BT) in combination with external beam radiation therapy (EBRT) in the treatment of patients with localised prostate cancer. Over a period of 16 years, >2,000 patients with prostate cancer have been treated in Sweden with a combination of two fractions of 10 Gy Ir-192 HDR-BT and 50 Gy of fractionated EBRT. Although this treatment is usually well tolerated, there are biological and technical factors to be considered before and during the treatment of the patient to avoid side effects or under-treatment of the target volume. Some of the problems facing the doctors are transducer stability, needle deviation, target definition, target motion, pubic arch interference, concomitant diseases and tolerance doses for different organs at risk. These problems are discussed and possible solutions are presented in this study.

Morphological appearance, content of extracellular matrix and vascular density of lung metastases predicts permissiveness to infiltration by adoptively transferred natural killer and T cells

We have recently shown that adoptively transferred, IL-2-activated natural killer (A-NK) cells are able to eliminate well-established B16-F10.P1 melanoma lung metastases. However, some B16-F10.P1 lung metastases were resistant to infiltration by the A-NK cells and also resistant to the A-NK cell treatment. The infiltration-resistant (I-R) B16-F10.P1 metastases had a unique "compact" morphology compared to the "loose" morphology of the infiltration-permissive (I-P) metastases. Here, we show that I-P loose tumors and I-R compact tumors are also found in lung metastases of mouse Lewis lung carcinoma (3LL), MCA-102 sarcoma, and MC38 colon carcinoma as well as rat MADB106 mammary carcinoma origin. Furthermore, the infiltration resistance of the compact tumors is not restricted to A-NK cells, since PHA and IL-2 stimulated CD8+ T-cells (T-LAK cells) also infiltrated the compact tumors poorly. Analyses of tumors for extracellular matrix (ECM) components and PECAM-1(+) vasculature, revealed that the I-R lesions are hypovascularized and contain very little laminin, collagen and fibronectin. In contrast, the I-P loose tumors are well-vascularized and they contain high amounts of ECM components. Interestingly, the distribution pattern of ECM components in the I-P loose tumors is almost identical to that of the normal lung tissue, indicating that these tumors develop around the alveolar walls which provide the loose tumors with both a supporting tissue and a rich blood supply. In conclusion, tumor infiltration by activated NK and T cells correlates with the presence of ECM components and PECAM-1(+) vasculature in the malignant tissue. Thus, analysis of the distribution of ECM and vasculature in tumor biopsies may help select patients most likely to benefit from cellular adoptive immunotherapy.

Composition of coronary plaques obtained by directional atherectomy in stable angina: its relation to serum lipids and statin treatment

OBJECTIVES

The stability and inflammatory activity in atherosclerotic plaques may be modulated by lipids and lipoproteins as well as the pleiotropic effects of statins. The aim of this study was to analyse the effect of statin treatment as well as the relation of plasma lipids and lipoproteins to tissue composition in atherosclerotic plaques.

DESIGN

Patients with stable angina and coronary plaques suitable for directional coronary atherectomy (DCA) were randomized to atorvastatin (80 mg once daily) or placebo (29 randomized, 22 underwent DCA, 11/group). After an average treatment of 10 weeks, patients underwent DCA, tissue specimens were obtained, and the tissue composition was determined by immunohistochemistry.

RESULTS

Atorvastatin reduced the T-cell content, but did not change lipid, collagen, smooth muscle cell, or macrophage content. Plasma levels of apolipoprotein AI (apoAI) correlated positively with tissue collagen and inversely with metalloproteinase-9 and macrophage content. About half the specimens contained neutrophil granulocytes.

CONCLUSIONS

Short-term atorvastatin treatment tended to reduce the T-cell content of atherosclerotic plaques, indicating modulation of cell-mediated immunity. High plasma levels of apoAI correlated with increased collagen content and reduced inflammation, supporting the notion that plasma apoAI stabilizes atherosclerotic plaques. The significance of neutrophils in the lesions merits further study.

Stenting in small coronary arteries (SISCA) trial. A randomized comparison between balloon angioplasty and the heparin-coated beStent

OBJECTIVES

The purpose of this study was to assess the clinical and angiographic benefits of elective stenting in coronary arteries with a reference diameter of 2.1 to 3.0 mm, as compared with traditional percutaneous transluminal coronary angioplasty (PTCA).

BACKGROUND

The problems related to small-vessel stenting might be overcome using modern stents designed for small vessels, combined with effective antiplatelet therapy.

METHODS

In five centers, 145 patients with stable or unstable angina were randomly assigned to elective stenting treatment with the heparin (Hepamed)-coated beStent or PTCA. Control angiography was performed after six months. The primary end point was the minimal lumen diameter (MLD) at follow-up. Secondary end points were the restenosis rate, event-free survival and angina status.

RESULTS

At follow-up, there was a trend toward a larger MLD in the stent group (1.69 +/- 0.52 mm vs. 1.57 +/- 0.44 mm, p = 0.096). Event-free survival at follow-up was significantly higher in the stent group: 90.5% vs. 76.1% (p = 0.016). The restenosis rate was low in both groups (9.7% and 18.8% in the stent and PTCA groups, respectively; p = 0.15). Analyzed as treated, both the MLD and restenosis rate were significantly improved in patients who had stents as compared with PTCA.

CONCLUSIONS

In small coronary arteries, both PTCA and elective stenting are associated with good clinical and angiographic outcomes after six months. Compared with PTCA, elective treatment with the heparin-coated beStent improves the clinical outcome; however, there was only a nonsignificant trend toward angiographic improvement.

A quantitative model of the domain structure of the photosynthetic membrane

A model is presented that gives a quantitative picture of the distribution of the photosynthetic components in the photosynthetic membrane of higher plants. A salient feature of the model is that most of the pigments are located in the grana where photosystem I and II carry out linear electron transport, whereas the stroma lamellae, which harbour <20% of the pigments, carry out photosystem-I-mediated cyclic electron transport. This arrangement derives from the observation that more pigments are associated with photosystem I, which therefore captures more quanta than photosystem II. The excess pigments associated with photosystem I are thought to be located in the stroma lamellae.

Continued benefit of coronary stenting versus balloon angioplasty: five-year clinical follow-up of Benestent-I trial

OBJECTIVES

This study sought to establish whether the early favorable results in the Benestent-I randomized trial comparing elective Palmaz-Schatz stent implantation with balloon angioplasty in 516 patients with stable angina pectoris are maintained at 5 years.

BACKGROUND

The size of the required sample was based on a 40% reduction in clinical events in the stent group. Seven months and one-year follow-up in this trial showed a decreased incidence of restenosis and clinical events in patients randomized to stent implantation.

METHODS

Data at five years were collected by outpatient visit, via telephone and via the referring cardiologist. Three patients in the stent group and one in the percutaneous transluminal coronary angioplasty (PTCA) group were lost to follow-up at five years. Major clinical events, anginal status and use of cardiac medication were recorded according to the intention to treat principle.

RESULTS

No significant differences were found in anginal status and use of cardiac medication between the two groups. In the PTCA group, 27.3% of patients underwent target lesion revascularization (TLR) versus 17.2% of patients in the stent group (p = 0.008). No significant differences in mortality (5.9% vs. 3.1%), cerebrovascular accident (0.8% vs. 1.2%), myocardial infarction (9.4% vs. 6.3%) or coronary bypass surgery (11.7% vs. 9.8%) were found between the stent and PTCA groups, respectively. At five years, the event-free survival rate (59.8% vs. 65.6%; p = 0.20) between the stent and PTCA groups no longer achieved statistical significance.

CONCLUSIONS

The original 10% absolute difference in TLR in favor of the stent group has remained unchanged at five years, emphasizing the long-term stability of the stented target site.

Physical activity, symptoms of chest pain and dyspnea in patients with ischemic heart disease in relation to age before and two years after coronary artery bypass grafting

BACKGROUND

To describe limitation of physical activity, cause of limitation of physical activity and symptoms of dyspnea and chest pain in relation to age before and 2 years after coronary artery bypass grafting (CABG).

METHODS

All patients from Western Sweden who underwent CABG without concomitant procedures during 3 years in 1989-1991 answered questionnaires before, and 2 years after the operation. Patients were divided into 3 age groups of equal size i.e. 32-59 years, 60-67 years and > or = 68 years.

RESULTS

In total, 2121 patients participated in the evaluation. The overall 2 year mortality in the 3 age groups was 3.8%, 6.8% and 12.2% (p<0.001). Limitation of physical activity was significantly associated with age prior to surgery but not thereafter. Improvement in physical activity, following CABG, was significant in all age groups. The proportion of patients being free of dyspnea increased markedly regardless of age. The number of chest pain attacks was associated with age after CABG, i.e. fewer attacks in the elderly, but such an association was not found prior to surgery. Improvement in number of chest pain attacks was more marked in the elderly.

CONCLUSIONS

Physical activity improved similarly in all age groups after CABG. Attacks of chest pain, although significantly reduced in all age groups, seemed more effectively reduced in the elderly.

Characterization of Forssman and other antigen/antibody systems in vascularized mouse heart to rat xenotransplantation

In the present study, the nature of hyperacute xenograft rejection was closely studied in a vascularized mouse-to-rat transplantation model. Antibodies against mouse heart, erythrocytes and lymphocytes and against the Forssman antigen were raised in the rat. Upon heterotopic heart transplantation the respective antisera were intravenously (i.v.) injected. Passive transfer of antiheart, antierythrocyte or antilymphocyte serum resulted in hyperacute rejection of the transplanted mouse heart. Subfractionation of the antiheart serum showed that the capacity to induce hyperacute rejection was carried by the immunoglobulin (Ig)G fraction. When antierythrocyte serum adsorbed with mouse erythrocytes was administered the cardiac grafts remained beating. To the contrary, antilymphocyte serum adsorbed with erythrocytes still had the capacity to induce hyperacute rejection. None of the rats that had previously been challenged with the Forssman antigen rejected their grafts hyperacutely. Subsequent investigations by electron microscopy revealed that the Forssman antigen is expressed on dendritic cells (DC) adjacent to the vessels, but not on the vascular endothelium, thus explaining the inability of the anti-Forssman serum to induce hyperacute rejection. Taken together, we have demonstrated the existence of several xenoantigens that can be targets for antibody-mediated rejection, suggesting that more than one relevant xenoantigen exists also in more distantly related combinations, such as the pig-to-human combination.

The phenotypic heterogeneity of human natural killer cells: presence of at least 48 different subsets in the peripheral blood

Peripheral blood natural killer (NK) cells are usually defined as a homogeneous cell population. However, NK cells show heterogeneous expression of a diversity of cell surface molecules, which might reflect the diversity of NK-cell functions. Therefore, a more specific phenotypic definition of NK cells is necessary. In this study, we made an inventory of phenotypic subsets that are present within the peripheral blood NK-cell population of healthy donors based on differential expression of nine cell-surface markers. Using three-colour flow cytometric analysis we were able to define at least 48 different CD56(+) NK-cell subsets within the peripheral blood. This phenotypic heterogeneity appeared to be stable among healthy individuals, and was also steady within CD56(dim) and CD56(bright) NK populations, indicating a possible role for these subsets in NK-cell function or differentiation.

Expression of neutrophil collagenase (MMP-8) in Jurkat T leukemia cells and its role in invasion

BACKGROUND

Previous studies have shown that MMP-8, the neutrophil collagenase, was expressed in neutrophils, chondrocytes and rheumatoid synovial fibroblasts.

MATERIALS AND METHODS

We used semi-quantitative RT-PCR analysis, Western blotting, and immunofluorescence assays to determine the expression of MMP-8 in Jurkat T cells.

RESULTS

We have determined the expression of MMP-8 from Jurkat cells and the down-regulation of its expression by genistein, a principal soy isoflavone. Genistein inhibited the invasion of Jurkat cells through a model basement membrane by about 75%, similar to the inhibition by BB-94, a synthetic MMP inhibitor. Genistein also down-regulated the expression of MMP-13, but slightly up-regulated the expression of TIMP-1 and TIMP-2.

CONCLUSIONS

Our findings documented for the first time the expression of the neutrophil collagenase by a T-cell line. We also determined the inhibition of Jurkat cell invasion by genistein, which was in part mediated through the regulation of the expression of MMPs and TIMPs.

Expression of matrix metalloproteinases and their inhibitors by rat NK cells: inhibition of their expression by genistein

In this study, we describe rat NK cell-derived MMPs including membrane-type MMPs (MT-MMPs) and tissue inhibitors of MMP (TIMPs). RT-PCR analysis from cDNA of rat A-NK cells revealed mRNA for MMP-2, MMP-9, MMP-7, MMP-10, MMP-11, MMP-13, MT1-MMP, MT2-MMP, TIMP-1, and TIMP-2. The RNK-16 cells expressed mRNA for MMP-7, MMP-10, MMP-11, MT1-MMP, MT2-MMP, TIMP-1, and TIMP-2, in addition to MMP-3 and MMP-13. Western blot analysis confirmed proteins for MT1-MMP and MT2-MMP in RNK-16 cells. TIMP-1 in rat A-NK cells was present at molecular mass of 34-kDa protein which may represent a highly glycosylated form. Genistein, a natural isoflavone found in soybeans, inhibited proliferation of RNK-16 cells in dosage dependent manner. In addition, it down-regulated the expression of MMP-13, MT1-MMP, TIMP-1 and TIMP-2. Moreover, genistein greatly impaired the ability of RNK-16 cells to invade through a model basement membrane. This effect might be mediated by the observed down-regulation of MMP-13 and MT1-MMP.

2B4 stimulation of YT cells induces natural killer cell cytolytic function and invasiveness

2B4 is a surface molecule found on all human natural killer (NK) cells, a subset of CD8+ T cells, monocytes and basophils. It was originally identified on mouse NK cells and the subset of T cells that mediate non-major histocompatibility complex (MHC)-restricted killing. Recently,9 we have cloned the human homologue of 2B4 (h2B4) and found h2B4 to also mediate non-MHC-restricted cytotoxicity. In this study, we examine h2B4 in regulating various functions of NK cells using a human NK cell line YT, with monoclonal antibody (mAb) C1.7, an antibody that specifically recognizes h2B4. Ligation of surface 2B4 with mAb C1.7 increases YT's ability to destroy tumour cells. In the presence of mAb C1.7, the production of interferon-gamma (IFN-gamma) by YT cells is greatly enhanced. Engagement of surface 2B4 by mAb C1.7 downregulates the expression of h2B4 at the cell surface as well as the expression of h2B4 mRNA. Also, signalling through h2B4 causes the increased expression of matrix metalloproteinase-2, a member of the matrix degrading proteinase family. Thus, in addition to modulating cytolytic function and cytokine production of NK cells, activation through surface 2B4 may play a role in upregulating the machinery for degradation of extracellular matrices to promote invasion of the tumour by NK cells.

Secreted and membrane-associated matrix metalloproteinases of IL-2-activated NK cells and their inhibitors

We have previously documented that rat IL-2-activated NK (A-NK) cells produce matrix metalloproteinase-2 (MMP-2) and MMP-9. In this study, we describe mouse A-NK cell-derived MMPs, including MT-MMPs, and also TIMPs. RT-PCR analysis from cDNA of mouse A-NK cells revealed mRNA for MMP-2, MMP-9, MMP-11, MMP-13, MT1-MMP, MT2-MMP, TIMP-1, and TIMP-2. MMP-2 and MMP-9 expression was confirmed by gelatin zymography. Moreover, we report for the first time that MT-MMPs are expressed by NK cells, i.e., large granular lymphocytes as determined by both RT-PCR and Western blots. TIMP-1 expression was detected as a 29-kDa protein in Western blots. It is intriguing that TIMP-2 protein from A-NK cells was also detected as a 29-kDa protein, which is clearly different from the previously reported molecular mass of 21 kDa in mouse and human cells. In addition, inhibition of MMPs by BB-94, a selective inhibitor of MMP, significantly inhibited the ability of mouse A-NK cells to migrate through Matrigel, a model basement membrane. Taken together, these findings suggest that A-NK cells may therefore use multiple MMPs in various cellular functions, including degradation of various extracellular matrix molecules as they extravasate from blood vessels and accumulate within cancer metastases following their adoptive transfer.

Matrix metalloproteinases of human NK cells

We have previously reported that MMP-2 and MMP-9 are present in rat A-NK cells, and have recently documented that additional MMPs are present in rodent A-NK cells. To our knowledge only proMMP-9 has previously been reported for human NK and A-NK cells. Herein, we report for the first time the presence of MMP-2 and MT1-MMP in human NK cells. The importance of these enzymes for the migration of A-NK cells into tumor metastases is of great potential relevance. MMPs may be rate limiting in A-NK cells, following their adoptive transfer, to traverse basement membrane and accumulate within established cancer metastases, a likely pre-requisite to their cytolytic function. Human NK cells express and produce MMP-2, MMP-9, MT1-MMP and the inhibitor TIMP-1. Moreover, human A-NK cells degrade the extracellular matrix equivalent (Matrigel) in a seemingly IL-2 dependent manner. It is therefore likely that A-NK cell MMPs play crucial roles in contributing to A-NK cell localisation and positioning the cells in vivo to allow for triggering their cytolytic potential.

Continuous vectorcardiographic monitoring of ischemia during coronary angioplasty in patients with bundle-branch block

BACKGROUND

Patients with the combination of bundle-branch block and ischemic heart disease have a poor outcome. There is no established criterion for detection of transient ischemia when bundle-branch block is present.

OBJECTIVE

To elucidate vectorcardiographic changes during coronary angioplasty of patients with bundle-branch block.

DESIGN AND METHODS

The QRS complex and ST-segment changes of 29 patients with bundle-branch block were studied during elective coronary angioplasty using continuous vectorcardiography. Data for the patients with bundle-branch block were compared with data for narrow-QRS-complex controls, matched for the vessel dilated, sex, and age.

RESULTS

Patients with bundle-branch block were found to have more pronounced changes in the QRS-vector difference as a response to coronary occlusion than did controls. ST-vector magnitude responded in a similar way during coronary occlusion of patients with and without bundle-branch block but from different baselines. ST change-vector magnitude was found to be the most sensitive parameter for detection of ischemia in patients with bundle-branch block as well as for controls.

CONCLUSION

Monitoring of transient ischemia during coronary angioplasty for patients with bundle-branch block is feasible using continuous vectorcardiography. A change in ST vector magnitude > 100 microV is suggested to indicate significant ischemia in the presence of bundle-branch block.

Comparison of diabetic and non-diabetic patients referred for coronary angiography

AIM

To evaluate whether diabetic patients differ from non-diabetic patients when referred for coronary angiography regarding previous history, indication for and findings at coronary angiography, use of medication, exercise test results and mortality.

METHODS

Data were prospectively collected on patients referred for consideration of coronary revascularization to seven of the eight public Swedish heart centers that performed approximately 92% of all bypass operations in Sweden in 1994.

RESULTS

2762 patients were included of whom 406 (15%) had a history of diabetes mellitus. There was no difference in age or sex in the two groups. Chronic stable angina was the most common indication (73% in both groups) and only 3% were admitted due to silent ischemia. Diabetic patients had more severe symptoms (Canadian Cardiovascular Society III-IV) than non-diabetic patients (66% vs. 58%, p<0.01). They more frequently used ACE-inhibitors (33% vs. 19%, p<0.0001) and calcium channel blockers (47% vs. 40%, p<0.01) and more often had a diagnosis of arterial hypertension than non-diabetic patients (50% vs. 33%, p<0.0001). Diabetic patients more often had depressed myocardial function (EF<35%); 12% and 8%, respectively (p<0.01), and more extensive coronary artery disease (left main/3-VD; 48% vs. 37%, p<0.001). The mortality during the subsequent 21 months was 7.9% among diabetic patients and 3.6% among non-diabetic patients (p<0.001).

CONCLUSION

Among patients being referred for coronary angiography in Sweden, 15% were patients with a history of diabetes. They differed from patients without such a history by more often having severe symptoms and a higher prevalence of left main/triple vessel disease. Coronary angiography may thus be underused in diabetic patients with chest pain.

Esophageal dysfunction in syndrome X

Syndrome X is defined as anginal chest pain accompanied by objective signs of ischemia on exercise testing or myocardial scintigraphy, but with angiographically "normal" coronary arteries. The etiology of this enticing syndrome is still not known. Besides myocardial ischemia, esophageal dysfunction and visceral hypersensitivity may play a role in the development of pain. The purpose of this study was to study esophageal function and visceral sensitivity in patients with syndrome X. Twenty consecutive patients with the diagnosis of syndrome X were investigated with esophageal manometry and a 24-hour pH recording. Visceral esophageal sensitivity was explored by balloon distention of the distal esophagus, as well as by instillation of acid. Twelve patients (67% of the 18 evaluated) had some abnormality on 24-hour pH monitoring; 2 had abnormal global acid exposure time (pH <4) and 7 had symptoms coincidental with episodes of pH <4. Seven patients (35%) had esophageal dysmotility including 5 with the "nutcracker" esophagus. Esophageal hypersensitivity to acid (n = 9) or distention (n = 13) was seen in 14 of the 20 patients. Eleven patients received acid suppressive therapy that resulted in amelioration of chest pain in 8 (73%). Thus, results suggest that esophageal hypersensitivity rather than gross functional abnormality is an important factor for the development of chest pain in patients with syndrome X, and that acid in the context of a hypersensitive esophagus is the main culprit. Acid suppression may ameliorate pain in a substantial proportion of patients.

Cytolytic activities of IL-2 activated NK cells from MMTV/v-Ha-ras transgenic oncomice during tumor progression

IL-2 activated natural killer (A-NK) cells have the capacity to infiltrate metastatic tumors and lyse tumor cells. Nevertheless, adoptive immunotherapy with lymphokine-activated killer cells has been only modestly effective in the clinic and has not routinely provided long-term survival in patients with established cancer metastases. This may indicate the need for more carefully investigating the role of effector cells of the immune response, including A-NK cells, in models of tumor progression. Herein we describe the use of the MMTV/v-Ha-ras transgenic mouse model as a system for exploring the role of NK cells during tumor progression. We have examined the lytic capacity of A-NK cells generated from tumor-free and tumor-bearing transgenic oncomice against standard A-NK cell targets (YAC-1 and P815) in addition to tumor cells isolated from these animals. A-NK cells generated from mice without obvious tumor burden show higher lytic activity than A-NK cells generated from mice with evident tumors, i.e., those at a more advanced stage of tumor progression. Only long term (8-day) cultures of late passage A-NK cells generated from tumor-bearing mice showed significant increases in lytic activity over those generated from tumor-free mice. These results suggest that experimental protocols using transgenic oncomice at various stages of tumor growth may constitute a novel model for testing the role of A-NK cells for their capacity to interfere with cancer progression.

Effects of spinal cord stimulation on coronary blood flow velocity

BACKGROUND

Spinal cord stimulation (SCS) has been used in the treatment of severe angina pectoris since the 1980s. Several studies have shown both an antianginal and an anti-ischaemic effect. There are several theories about the mechanism behind the anti-ischaemic effect of SCS, including the possibility that it is dependent on an increase in coronary flow velocity.

OBJECTIVE

To determine if there were effects of SCS on coronary flow velocity during cardiac stress.

METHOD

Eight patients with severe anginal pain secondary to coronary artery disease who had been implanted with an SCS device were included in the study. In addition, four patients with syndrome X were examined. If possible, a Doppler guidewire was placed in the vessel corresponding to the ischaemic area revealed on a prior myocardial scintigram. A temporary pacemaker electrode was placed in the right atrium. Atrial pacing started at 80 beats/min and increased by 10 beats/min every 2 min until the patient experienced moderate angina; the pacing frequency was then maintained at the same level. After 2 min of pacing at this frequency, SCS treatment commenced; after a further 5 min, pacing was stopped. Throughout the procedure, coronary flow velocity, assessed as average peak velocity (APV), was monitored continually.

RESULTS

APV increased during pacing in all the patients with coronary artery disease (mean increase 53%; P < 0.02). There were no significant changes in APV during maximum pacing frequency when stimulation was introduced.

CONCLUSIONS

The results of this study do not support the theory that the anti-ischaemic effect of SCS is dependent on an increase in coronary flow velocity.

Preoperative left-ventricular ejection fraction does not influence the improvement in quality of life after coronary artery bypass surgery

Coronary artery bypass grafting (CABG) is an established treatment for angina pectoris which conveys relief of chest pain and improved physical performance. However, increased survival has only been observed in selected subgroups of patients with advanced coronary artery disease, particularly in the presence of depressed left-ventricular ejection fraction (LVEF). It is therefore of interest to study whether the outcome in terms of quality of life (QoL) is also more favorable in candidates with depressed LVEF. All patients who underwent CABG without concomitant valve surgery in western Sweden between 6.1988 and 6.1991 (n = 2121) were sent questionnaires on QoL involving 3 different instruments, the Physical Activity Score, the Nottingham Health Profile, and the Psychological General Well-being Index. They were submitted before surgery and 3 times in the 2 years thereafter. QoL was improved on all postoperative occasions. The degree of improvement was not associated with preoperative LVEF for any of the instruments. The postoperative Physical Activity Score was associated with preoperative LVEF. The other instruments showed no such association with LVEF. The improvement in QoL during 2 years after CABG is not dependent on the LVEF determined prior to operation. Self-estimated physical abilities are postoperatively associated with preoperative LVEF whereas health-related QoL and general well-being are not.

Sustained benefit of stenting chronic coronary occlusion: long-term clinical follow-up of the Stenting in Chronic Coronary Occlusion (SICCO) study

OBJECTIVES

This study assessed the long-term clinical outcome of stenting chronic occlusions.

BACKGROUND

In the Stenting in Chronic Coronary Occlusion (SICCO) study, patients were randomized to additional stent implantation (n = 58) or not (n = 59) after successful recanalization and dilation of a chronic coronary occlusion. Palmaz-Schatz stents were used with full anticoagulation. The previously published 6-month angiographic follow-up results showed reduction of the restenosis rate from 74% to 32%.

METHODS

The primary end point was the occurrence of major adverse cardiac events (cardiac death, lesion-related acute myocardial infarction, repeat lesion-related revascularization or angiographic documentation of reocclusion).

RESULTS

Late clinical follow-up was obtained in all patients at 33 +/- 6 months. Major adverse cardiac events occurred in 14 patients (24.1%) in the stent group compared with 35 patients (59.3%) in the percutaneous transluminal coronary angioplasty (PTCA) group (odds ratio 0.22, 95% confidence interval 0.10 to 0.49, p = 0.0002). Target vessel revascularization (including failed PTCA attempts) was performed in 24% of the stent group and in 53% of the PTCA group (p = 0.002). There were no events in the stent group after 8 months, whereas events continued to occur in the PTCA group. By multivariate analysis, allocation to the PTCA group, left anterior descending coronary artery lesion and lesion length were significantly related to the development of major adverse cardiac events.

CONCLUSIONS

These data demonstrate the long-term safety and clinical benefit of stenting recanalized chronic occlusions. There is a continued risk of late clinical events related to nonstented lesions. Implantation of an intracoronary stent should therefore be considered after successful opening of a chronic coronary occlusion.

Matrix metalloproteinases produced by rat IL-2-activated NK cells

We have previously documented that adoptively transferred IL-2-activated NK (A-NK) cells can accumulate within cancer metastases. Electron microscopic studies of pulmonary metastases have revealed that adoptively transferred A-NK cells that accumulate within metastases bind to endothelial cells and are able to traverse basement membranes. We have now extended these morphologic studies. We report that rat A-NK cells produce two matrix metalloproteinases: MMP-2 and MMP-9, as determined by SDS-PAGE gelatin zymography. These activities are inhibited following incubation with BB-94 (batimastat), a specific inhibitor of matrix metalloproteinases but not with 3,4-dichloroisocoumarin, an inhibitor of neutral serine proteases. The identity of MMP-2 was confirmed by Western blots using a polyclonal Ab against human MMP-2, whereas reverse transcriptase-PCR analysis of mRNA extracts of A-NK cells has confirmed the presence of MMP-9. In addition, we report for the first time that A-NK cells can migrate through a model basement membrane-like extracellular matrix. Moreover, the ability of A-NK cells to migrate through this model basement membrane was partially inhibited by BB-94; however, BB-94 has no effect on A-NK cell-mediated cytotoxicity, suggesting that matrix metalloproteinases do not contribute to cytolytic function of A-NK cells. In sum, our studies show that A-NK cells employ BB-94-inhibitable matrix metalloproteinases to degrade extracellular matrices. This suggests that matrix metalloproteinases may play a role in the accumulation of A-NK cells within cancer metastases.

Mortality and morbidity among patients who undergo combined valve and coronary artery bypass surgery: early and late results

AIM

To describe mortality and morbidity early and late after combined valve surgery and coronary artery bypass grafting (CABG) as compared with CABG alone.

PATIENTS AND METHODS

All patients from western Sweden in whom CABG in combination with valve surgery or CABG alone was carried out in 1988-1991.

RESULTS

Among 2116 patients who underwent CABG, 35 (2%) had this combined with mitral valve surgery and 134 (6%) had this combined with aortic valve surgery, whereas the remaining 92% underwent CABG alone. Patients who underwent combined valve surgery and CABG were older, included more women and had a higher prevalence of previous congestive heart failure and renal dysfunction but on the other hand a less severe coronary artery disease. Among patients who underwent mitral valve surgery in combination with CABG the mortality over the subsequent 5 years was 45%). The corresponding figure for patients who underwent aortic valve surgery in combination with CABG was 24%. Both were higher than for CABG alone (14%; P < 0.0001 and P = 0.003, respectively). In a stepwise multiple regression model mitral valve surgery in combination with CABG was found to be an independent significant predictor for death but aortic valve surgery in combination with CABG was not. Among patients who underwent mitral valve surgery in combination with CABG and were discharged alive from hospital 77% were rehospitalized during the 2 years following the operation as compared with 48% among patients who underwent aortic valve surgery in combination with CABG and 43% among patients with CABG alone. Multiple regression identified mitral valve surgery in combination with CABG as a significant independent predictor for rehospitalization but not aortic valve plus CABG.

CONCLUSION

Among patients who either underwent CABG in combination with mitral valve surgery or aortic valve surgery or CABG alone, mitral valve surgery in combination with CABG was independently associated with death and rehospitalization, but the combination of aortic valve surgery and CABG was not.

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

We describe the 2- and 5-year prognoses following coronary artery bypass grafting (CABG) in relation to smoking habits among consecutive patients being operated on in western Sweden during a 3-year period. Among the 2,121 patients, 10.2% admitted smoking at coronary angiography as compared with 7.5% 2 years after CABG (NS). Among smokers, the mortality during the subsequent 2 years was 8.9% as compared with 6.5% for exsmokers and 7.3% for never smokers (NS). During the 5-year follow-up, smokers had a mortality of 18.8% as compared with 13.6% for exsmokers and 12.5% for never smokers (p = 0.03). When correcting for dissimilarities in previous history, smoking was a strongly significant independent (p < 0.0001) predictor of 5-year mortality.

Limitation of physical activity, dyspnea and chest pain prior to and during two years after coronary artery bypass grafting in relation to a history of hypertension

AIM

To describe the limitation of physical activity, the cause of limitation of physical activity and symptoms of dyspnea and chest pain before and 2 years after coronary artery bypass grafting (CABG) in relation to a history of hypertension.

METHODS

All patients from western Sweden who underwent CABG between 1988 and 1991 were approached with a questionnaire--prior to, 3 months and 2 years after CABG--evaluating the issues raised above.

RESULTS

Of 2121 patients, 37% had a history of hypertension. By 3 months after CABG, physical activity tolerance had improved markedly and in a similar way for both hypertensive (p<0.001) and non-hypertensive patients (p<0.001); this level was sustained for 2 years. Absence of dyspnea increased markedly and similarly among both hypertensive and non-hypertensive patients (p < 0.001) after CABG. The presence of chest pain decreased markedly and similarly among hypertensive (p<0.001) and non-hypertensive patients (p<0.001), both 3 months and 2 years after compared to prior to the operation.

CONCLUSION

There was a marked improvement in terms of physical activity and cardiovascular symptoms 3 months and 2 years after CABG as compared with the situation prior to the operation. A previous history of hypertension did not seem to affect these results.

Intracoronary blockade of angiotensin-converting enzyme in humans: interaction with cardiac sympathetic neurotransmission?

The present study was designed to identify an interaction between the renin-angiotensin system and noradrenergic transmission in the human heart. It is still under debate whether angiotensin II facilitates noradrenaline release in the heart. Clinical studies of congestive heart failure, involving systemic angiotensin-converting enzyme (ACE) inhibitor administration, have indicated anti-adrenergic effects, without giving a clear mechanistic picture. The influence on cardiac sympathetic transmission by local intracardiac administration of an ACE inhibitor has not been determined. Seven angina patients with normal left ventricular function, who underwent control coronary angiography after successful percutaneous transluminal coronary angioplasty were studied. Baseline measurements of haemodynamics and total and cardiac noradrenaline spillover were followed by handgrip exercise in the absence and presence of intracoronary enalaprilat infusion (0.05 mg min-1, 1 mL min-1). Baseline total body and cardiac noradrenaline spillover remained unchanged following intracoronary enalaprilat infusion, being 3745 +/- 349 and 3896 +/- 257 pmol min-1, and 148 +/- 56 and 149 +/- 55 pmol min-1, before and after drug administration, respectively. Mean arterial pressure, peripheral plasma renin activity and angiotensin II levels were also unaffected by enalaprilat infusion. During handgrip exercise procedures, both total body and cardiac noradrenaline spillover increased substantially, showing no reduction in the presence of intracardiac enalaprilat. Direct administration of the ACE inhibitor enalaprilat to the human heart failed to attenuate cardiac sympathetic drive during baseline conditions or following cardiac adrenergic activation by handgrip exercise. Thus, in the non-failing heart, without chronic adrenergic activation, no angiotensin II-facilitated effect on cardiac noradrenaline spillover could be detected.

Death, mode of death, morbidity, and rehospitalization after coronary artery bypass grafting in relation to occurrence of and time since a previous myocardial infarction

To describe the prognosis during 2 years after coronary artery bypass grafting (CABG) in relation to occurrence of and time since a previous acute myocardial infarction (AMI), data of all patients in western Sweden who underwent CABG without simultaneous valve surgery in the period June 1988-June 1991 were evaluated. In all, 2120 patients were included in the analyses. Of these, 1296 (61%) had a history of AMI and 127 (6%) had suffered an AMI within the last month before CABG. Mortality during the first 30 days after CABG was for patients with no previous AMI, previous AMI > 30 days prior to CABG, and previous AMI < or = 30 days prior to CABG 2.4%, 4.1%, and 5.5%, respectively (p < 0.05). The corresponding figures for the period between 30 days and 2 years after CABG were 3.6%, 4.4%, and 3.4% respectively (NS). In a multivariate analysis among patients with a previous AMI, a recent infarction (< or = 30 days prior to CABG) did not turn out as an independent predictor of death during 2 years of follow-up. A history of AMI was associated with increased mortality during the first 30 days but not thereafter, but recent AMI was not an independent predictor of total 2-year mortality.

Predictors of hospital readmission two years after coronary artery bypass grafting

OBJECTIVE

To determine the clinical factors before, and in association with, coronary artery bypass grafting (CABG) that increase the risk of readmission to hospital in the first two years after surgery.

PATIENTS

All patients in western Sweden who had CABG without simultaneous valve surgery between 1 June 1988 and 1 June 1991.

METHODS

All patients who were readmitted to hospital were evaluated by postal inquiry and hospital records.

RESULTS

A total of 2121 patients were operated on, of whom 2037 were discharged from hospital. Information regarding readmission was missing in four patients, leaving 2033 patients; 44% were readmitted to hospital. The most common reasons for readmission were angina pectoris and congestive heart failure. There were 12 independent significant predictors for readmission: clinical history (a previous history of either congestive heart failure or myocardial infarction, or CABG); acute operation; postoperative complications (time in intensive care unit greater than two days, neurological complications); clinical findings four to seven days after the operation (arrhythmia, systolic murmur equivalent to mitral regurgitation); medication four to seven days after the operation (antidiabetics, diuretics for heart failure, other antiarrhythmics (other than beta blockers, calcium antagonists, and digitalis), and lack of treatment with aspirin).

CONCLUSION

44% of patients were readmitted to hospital two years after CABG. The most common reasons for readmission were angina pectoris and congestive heart failure. Four clinical markers predicted readmission: clinical history; acute operation status; postoperative complications; and clinical findings and medication four to seven days after operation.

Morbidity and use of medical resources in patients with chest pain and normal or near-normal coronary arteries

To evaluate morbidity and use of medical resources in patients with chest pain and normal or near-normal coronary angiograms: 2,639 consecutive patients who underwent coronary angiograms due to chest pain were registered. Two years thereafter all patients who showed normal or near-normal coronary angiograms were approached with a questionnaire regarding hospitalization during the last 4 years (2 years before and 2 years after angiography). All medical files were also examined. Of the patients who underwent angiography, 163 (6%) had no significant stenoses, and of these, 113 showed complete normal angiograms and 50 showed mild (i.e. <50%) stenoses. During the 2 years before diagnostic angiogram, 66% of the patients were hospitalized compared with only 35% during 2 years after angiography (p <0.001). The reduction in hospitalization was due to curtailed utilization of medical resources for cardiac reasons; mean days in hospital was 6.6 days before angiography versus 2.8 days after (p <0.001). There were no significant differences in hospitalization when comparing patients with mild stenoses and completely normal angiograms. There were, furthermore, no differences between patients with positive or negative exercise tests. Thus, the need for hospitalization is significantly reduced after a diagnostic angiogram reveals normal or near-normal coronary arteries.

Stenting in Chronic Coronary Occlusion (SICCO): a randomized, controlled trial of adding stent implantation after successful angioplasty

OBJECTIVES

This study investigated whether stenting improves long-term results after recanalization of chronic coronary occlusions.

BACKGROUND

Restenosis is common after percutaneous transluminal coronary angioplasty (PTCA) of chronic coronary occlusions. Stenting has been suggested as a means of improving results, but its use has not previously been investigated in a randomized trial.

METHODS

We randomly assigned 119 patients with a satisfactory result after successful recanalization by PTCA of a chronic coronary occlusion to 1) a control (PTCA) group with no other intervention, or 2) a group in which PTCA was followed by implantation of Palmaz-Schatz stents with full anticoagulation. Coronary angiography was performed before randomization, after stenting and at 6-month follow-up.

RESULTS

Inguinal bleeding was more frequent in the stent group. There were no deaths. One patient with stenting had a myocardial infarction. Subacute occlusion within 2 weeks occurred in four patients in the stent group and in three in the PTCA group. At follow-up, 57% of patients with stenting were free from angina compared with 24% of patients with PTCA only (p < 0.001). Angiographic follow-up data were available in 114 patients. Restenosis (> or = 50% diameter stenosis) developed in 32% of patients with stenting and in 74% of patients with PTCA only (p < 0.001); reocclusion occurred in 12% and 26%, respectively (p = 0.058). Minimal lumen diameter (mean +/- SD) at follow-up was 1.92 +/- 0.95 mm and 1.11 +/- 0.78 mm, respectively (p < 0.001). Target lesion revascularization within 300 days was less frequent in patients with stenting than in patients with PTCA only (22% vs. 42%, p = 0.025).

CONCLUSIONS

Stent implantation improved long-term angiographic and clinical results after PTCA of chronic coronary occlusions and is thus recommended regardless of the primary PTCA result.

Death, mode of death, morbidity and requirement for rehospitalization during 2 years after coronary artery bypass grafting in relation to preoperative ejection fraction

OBJECTIVE

To describe the impact of ejection fraction on the prognosis during 2 years after coronary artery bypass grafting (CABG).

PATIENTS

All patients in western Sweden who underwent CABG without concomitant valve surgery between June 1988 and June 1991.

RESULTS

In all, 2121 patients were operated upon and information on ejection fraction was available for 1961 patients (92%). Of these patients, 178 (9%) had an ejection fraction < 40%, 517 (26%) an ejection fraction of 40-59% and 1266 (65%) an ejection fraction > or = 60%. In these groups the mortalities during the first 30 days after CABG were 5.1, 4.3 and 2.2%, respectively (P < 0.01). The corresponding values for mortalities between 30 days and 2 years were 7.7, 4.3 and 3.3%, respectively (P < 0.01). Patients with a lower ejection fraction were more frequently men and more frequently had a history of cardiovascular disease. In multivariate analysis the preoperative ejection fraction was an independent predictor for total 2-year mortality. Patients with a low ejection fraction died more frequently in association with ventricular fibrillation. Morbidity was, with the exception of that for rehospitalization due to heart failure and infection, not associated significantly with the preoperative ejection fraction.

CONCLUSION

During the 2 years after CABG a low preoperative ejection fraction was associated with a higher mortality, but the association with morbidity was more complex.

The cost-benefit balance of coronary artery bypass grafting: need for hospitalization during the two years before and the two years after

To derive and compare the need for hospitalization during 2 years prior to coronary artery bypass grafting (CABG) and 2 years after, all the patients from western Sweden in whom CABG without simultaneous valve surgery was performed between June 1988 and June 1991 were evaluated. Hospitalization prior to and after surgery was derived via questionnaires sent to the patients and via data from their hospital medical record forms. In all, 2099 patients were studied. The mean total number of days in hospital was 16 during the 2 years before and 24 including surgery and postoperative complications during the 2 years after the operation (p < 0.001). When the days for operation and postoperative complications were excluded, the mean number of days after operation was 7 (p < 0.001). Hospitalization due to myocardial infarction, angina pectoris, percutaneous transluminal coronary angioplasty and other investigations for heart disease were significantly reduced after CABG. On the other hand, hospitalization due to chest pain with causes other than ischemic heart disease, congestive heart failure, arrhythmias, and reoperation was more frequent during the 2 years after surgery. The total number of days in hospital was higher during the 2 years after CABG than during the 2 years before, despite the fact that hospitalization due to ischemic events was significantly reduced after the operation.

Mortality and morbidity in diabetic and nondiabetic patients during a 2-year period after coronary artery bypass grafting

OBJECTIVE

To describe mortality and morbidity during a 2-year period after coronary artery bypass grafting (CABG) among diabetic and nondiabetic patients.

RESEARCH DESIGN AND METHODS

All the patients in western Sweden in whom CABG was undertaken between June 1988 and June 1991 and in whom concomitant procedures were not performed were registered prospectively. The study was a prospective follow-up.

RESULTS

Diabetic patients (n = 268) differed from nondiabetic patients (n = 1,859) in that more women were included, and the patients more frequently had a previous history of myocardial infarction (MI), hypertension, congestive heart failure, intermittent claudication, and obesity. Diabetic patients more frequently required reoperation and had a higher incidence of peri- and postoperative neurological complications. Mortality during the 30 days after CABG was 6.7% in diabetic patients versus 3.0% in nondiabetic patients (P < 0.01). Mortality between day 30 and 2 years was 7.8 and 3.6%, respectively (P < 0.01). During 2 years of follow-up, a history of diabetes appeared to be a significant independent predictor of death. Whereas the development of MI after discharge from the hospital did not significantly differ between the two groups; 6.3% of diabetic patients developed stroke versus 2.5% in nondiabetic patients (P < 0.001).

CONCLUSIONS

Diabetic patients have a mortality rate during the 2-year period after CABG that is about twice that of nondiabetic patients during both the early and late phase after the operation.