Rhythm versus rate control in patients with newly diagnosed atrial fibrillation: observations from the GARFIELD-AF registry

Background

Atrial fibrillation is associated with considerable morbidity and mortality. Real-world reports on the effect of early rhythm control on patient outcomes in patient with recent onset atrial fibrillation are limited.

Purpose

To assess the effect of early rhythm versus rate control on clinical outcomes in patients with newly diagnosed non-valvular atrial fibrillation.

Method

The Global Anticoagulant Registry in the FIELD-AF (GARFIELD-AF) is a non-interventional registry of adult (≥18 years) patients with newly diagnosed atrial fibrillation (≤ six weeks' duration) and at least one investigator determined risk factor for stroke. Patients were enrolled in 1317 participating sites in 35 countries between March 2010 and August 2016. Patients with permanent atrial fibrillation were excluded. Stratification to rhythm or rate control was based on treatment strategy initiated at baseline (≤48 days post enrolment). Rhythm control was defined as investigator reported initiation of rhythm control (antiarrhythmic drug(s), cardioversion, or ablation – alone or in combination with rate modifiers). Rate control was defined as investigator reported initiation of rate control and absence of rhythm control therapy. Overlap propensity weighting and Cox proportional-hazards models were used to evaluate effect on outcomes.

Results

Of 45,382 included patients, 23,858 (52.6%) received rhythm control and 21,524 (47.4%) rate control. Rates of rhythm control were similar throughout the study time period (52.7% in 2010/2011, 54.2% in 2015/2016). Patients in the rhythm control group were younger (median age (Q1; Q3) 68.0 (60.0; 76.0) versus 73.0 (65.0; 79.0)), had lower rates of prior stroke/transitory ischemic attack/systemic embolism (9.4% vs 13.0%), and a lower median GARFIELD death score (4.0 (2.3; 7.5) versus 5.1 (2.8; 9.2)). Median CHA2DS2-VASc Scores were 3.0 (2.0; 4.0) in both groups. Rate of anticoagulation treatment was similar in the rhythm and rate control group (66.0% versus 65.5%). After propensity score overlap weighting, patients of the two groups were well balanced on all observed characteristics.

Event rates per 100 person-years (95% confidence interval [CI]) over two years follow-up in the rhythm and rate control group were 2.94 (2.78–3.10) versus 4.43 (4.22–4.64) for mortality, 0.84 (0.75–0.92) versus 1.16 (1.05–1.27) for non-haemorrhagic stroke/systemic embolism and 0.84 (0.76–0.93) versus 1.16 (1.06–1.27) for major bleeding. Adjusted hazard ratios (95% CI) for the same time period were 0.85 (0.79–0.92), 0.84 (0.72–0.97) and 0.9 (0.78–1.04).

Conclusion

In this large, internation registry, a rhythm control strategy was initiated at baseline in about half of the patients with newly diagnosed non-valvular atrial fibrillation. After adjustment for confounding factors, a significantly lower risk of all-cause mortality and non-haemorrhagic stroke/systemic embolism were observed for patients that received an early rhythm control strategy.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the Thrombosis Research Institute (London, UK).

Association between clinical frailty, illness severity and post-discharge survival: a prospective cohort study of older medical inpatients in Norway

Aim

To assess impact of frailty screening and two markers of illness severity on survival following discharge from the hospital.

Findings

Independently of age, ward (acute geriatric and general medical) and comorbidity, both higher degree of frailty and illness severity associated with reduced survival probability following discharge. The impact of frailty on survival was higher in those experiencing high clinical and laboratory illness severity.

Message

The prognostic value of frailty screening increased when performed in conjunction with two markers of illness severity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00555-8.

Purpose

Study associations between frailty, illness severity and post-discharge survival in older adults admitted to medical wards with acute clinical conditions.

Methods

Prospective cohort study of 195 individuals (mean age 86; 63% females) admitted to two medical wards with acute illness, followed up for all-cause mortality for 20 months after discharge. Ward physicians screened for frailty and quantified its degree from one to eight using Clinical Frailty Scale (CFS), while clinical illness severity was estimated by New Early Warning Score 2 (NEWS2) and laboratory illness severity was calculated by a frailty index (FI-lab) using routine blood tests.

Results

CFS, NEWS2 and FI-lab scores were independently associated with post-discharge survival in an adjusted Cox proportional hazards model with age, ward category (acute geriatric and general medical) and comorbidity as covariates. Adjusted hazard ratios and 95% confidence intervals were 1.54 (1.24–1.91) for CFS, 1.12 (1.03–1.23) for NEWS2, and 1.02 (1.00–1.05) for FI-lab. A frailty × illness severity category interaction effect (p = 0.003), suggested that the impact of frailty on survival was greater in those experiencing higher levels of illness severity. Among patients with at least moderate frailty (CFS six to eight) and high illness severity according to both NEWS2 and FI-lab, two (13%) were alive at follow-up.

Conclusion

Frailty screening aided prognostication of survival following discharge in older acutely ill persons admitted to medical wards. The prognostic value of frailty increased when combined with readily available illness severity markers acquired during admission.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00555-8.

Administration of the Mitochondrial Permeability Transition Pore Inhibitor, TRO40303, prior to Primary Percutaneous Coronary Intervention, Does Not Affect the Levels of Pro-Inflammatory Cytokines or Acute-Phase Proteins

Objectives: In the MITOCARE study, reperfusion injury was not prevented after administration of the mitochondrial permeability transition pore (mPTP) opening inhibitor, TRO40303, in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). The effects of TRO40303 on pro-inflammatory cytokines and acute-phase proteins were assessed. Methods: STEMI patients (n = 163, mean age 62 years) with chest pain within 6 h before admission for pPCI were randomized to intravenous bolus of TRO40303 (n = 83) or placebo (n = 80) prior to reperfusion. We tested whether the groups differed in levels of IL-1β, IL-6, IL-10, TNF, and high-sensitive C-reactive protein at various time points (0, 12, and 72 h) after PCI. Further, potential differences between groups in the change of biomarker levels between 0 and 72 h, 0 and 12 h, and 12 and 72 h were tested. Results: There were no statistically significant differences between the two groups, neither in levels of pro-inflammatory cytokines nor in levels of acute-phase proteins, and there were no statistically significant differences in the change of biomarker levels between the groups considering the time intervals from 0 to 72 h, from 0 to 12 h, and from 12 to 72 h. Conclusion: The administration of the mPTP, TRO40303, prior to reperfusion does not alter the pharmacokinetics of pro-inflammatory cytokines or acute-phase proteins during the first 72 h after PCI.

Re-exploration for hemorrhage following open heart surgery differentiation on the causes of bleeding and the impact on patient outcomes

OBJECTIVES

To differentiate surgical bleeding requiring re-exploration from postoperative coagulopathy and determine the differences in patient outcomes.

METHODS

This was a retrospective chart review of 2,263 adult patients undergoing elective and emergency open heart procedures encompassing coronary artery bypass, valvular, and a combined procedure to determine the impact of source of bleeding leading to re-exploration.

RESULTS

Eighty-two patients (3.6%) required re-exploration. Sixty-six percent had surgical bleeding; the remaining 34% were coagulopathic. Postoperative coagulopathy was associated with preoperative heparin use (37% vs. 19.9% for controls p<0.05). Re-operative procedures combined bypass/ valve (p<0.001) and prolonged cardiopulmonary bypass and aortic cross-clamp times (p<0.05) were more prevalent in the coagulopathy group. Postoperative inotrope use was increased in patients who were re-explored (p<0.001), as were cardiac, pulmonary, renal and abdominal complications (p<0.001), and in all cases those patients with medically related bleeding had worse acute outcomes than the group with surgical causes for re-exploration. The hospital stay was prolonged for both patients with surgical bleeding (23.5 days) and patients with coagulopathy (27.1 days) compared to patients not undergoing re-exploration for bleeding (12.0 days, p<0.001). Survival was 91.3% for patients with surgical bleeding, 87.5% for patients with coagulopathy, and 98.0% for all others (p<0.01).

CONCLUSIONS

Severe postoperative hemorrhage is associated with significant morbidity and increased mortality. Postoperative hospital stay, morbidity, and mortality were significantly worse in patients suffering from coagulopathy when compared to those patients with hemorrhage from surgical causes.

Comparison of internal cardioverter defibrillator implantation techniques: subpectoral position

BACKGROUND

To compare surgical techniques for subpectoral implantation of internal cardioverter defibrillator (ICD).

METHODS

Sequential comparison with review of the literature.

SETTING

University Hospital.

PARTICIPANTS

the patients requiring ICD.

INTERVENTIONS

ICD insertions and device testing.

MEASUREMENTS

defibrillation and pacing thresholds, defibrillator lead impedance, operative time, and proximity of generator site to midline, clinical outcomes.

RESULTS

Comparable efficacy in defibrillation, surgical time and medial placement. No wound infections, seromas or lead dislodgments. Preservation of pectoral muscle integrity.

CONCLUSIONS

Lateral single incision subpectoral ICD generator placement can be applied consistently with good RESULTS.

Comparison of the flow capacity of free arterial grafts and saphenous vein grafts for coronary bypass surgery

There is controversy regarding the flow reserve and capacity of arterial conduits to meet the needs of the myocardium. This study compared flow in 22 free arterial bypasses to 15 saphenous vein grafts in procedures involving twenty patients. To assess the maximal flow possible, (flow capacity) graft flow was measured using a calibrated pump while perfusing blood cardioplegia through the conduit and distal anastomosis during cardiac arrest (no competitive flow). This assessment was subsequently confirmed with whole blood during myocardial contraction while on cardiopulmonary bypass. Twenty-two free arterial grafts were used; 15 right internal mammary artery grafts, 4 right gastroepiploic grafts, 3 inferior epigastric artery grafts, and 3 sequential bypasses. Free arterial conduit flow ranged from 50 to 180cc/ml, with an average flow of 102.5+/-28.5ml/min as compared to saphenous vein graft flow, 102+/-28 ml/min. No correlation of flow with the conduit size was found. Arterial graft flow demonstrated a mild correlation with the size of the native coronary artery bypassed (R=0.47, P</=0.02).

CONCLUSIONS

Basal flow through free arterial grafts is equivalent to saphenous vein grafts and is primarily determined by the native coronary vessels. The flow reserve for free arterial conduits is more than adequate for coronary bypass surgery.

Thoracic organ donor characteristics associated with successful lung procurement

PURPOSE

A shortage of suitable donors is the major impediment to clinical lung transplantation. The rate of lung recovery from potential donors is lower than that for other organs. The purpose of this study was to evaluate what factors could be modified to improve the rate of cadaver lung recovery.

METHODS

We performed a retrospective review of records from all thoracic organ donors procured by the California Transplant Donor Network between 1 January 1995 and 31 May 1997 (251 donors) to determine which donor management factors were associated with an increased likelihood of successful lung procurement.

RESULTS

There were 88 lung donors (L) and 163 donors from which hearts but no lungs were procured (H). Longer time to donor network referral was associated with a reduced chance for successful lung procurement. Donor age, cause of death, and time of admission were not important factors. Most donors in this study had an acceptable A-a gradient at admission to the hospital but lung function deteriorated in group H. Corticosteroid usage and initially clear breath sounds were independent predictors of successful procurement by multivariate analysis.

CONCLUSIONS

Early contact with the donor referral network, and corticosteroids may help to improve the lung procurement rate from potential donors.

Based on acute outcomes, "all arterial" coronary bypass surgery should be performed on younger elective patients

OBJECTIVES

This study evaluated acute results as a function of the number of arterial conduits used to compare procedural differences and the subsequent effects on acute outcomes in selected patient populations.

BACKGROUND

All arterial operations may provide better long-term results for younger patients undergoing coronary bypass surgery (CABG). However, concerns regarding additional morbidity when using multiple arterial conduits have inhibited their use.

METHODS

The study comprised a retrospective review of patients (2,586) undergoing CABG. Group 1 consists of single artery vein graft (1,755). Group 2: two arteries were used in addition to vein grafts (209). Group 3: three or more arterial conduits were used, with or without vein grafts (116). Group 4: only vein grafts were used (506).

RESULTS

Patients undergoing primarily arterial procedures, Group 2 and 3, were younger, had a better exercise profile, less history of myocardial infarction (MI), had less left ventricular dysfunction. There were also fewer emergencies, co-morbidities and associated procedures in this group. The cardiopulmonary bypass and cross clamp times were longer in those procedures with three or more arteries; however, this difference was only thirteen and fourteen minutes, respectively. Post-operative complications were higher in patients in the vein only group. The hospital stay and mortality was equivalent among groups in which an arterial bypass was used and better than those in which only vein grafts were used.

CONCLUSIONS

For younger patients, "all arterial operations," require only minimal increases in ischemic and operative times, which do not affect acute outcomes.

Giant tumors of the chest: preoperative embolization and resection

Giant tumors of the chest are rare. These tumors comprise a spectrum of disease from benign lesions to highly aggressive malignant tumors with cells of origin in the pleura, pulmonary parenchyma, blood vessels, thymus, and connective tissues. We report four cases of giant tumors of the thorax treated with preoperative arterial embolization followed by complete surgical resection. Their diagnostic and treatment courses, imaging, and pathology are described.

Cotton boll abscission and yield losses associated with first-instar bollworm (Lepidoptera: Noctuidae) injury to nontransgenic and transgenic Bt cotton

Field tests were conducted in northeastern Louisiana to determine the effects of infestations by Helicoverpa zea (Boddie) on cotton bolls of varying ages. First instars were caged on bolls of nontransgenic ('Deltapine 5415') or transgenic Bacillus thuringiensis Berliner variety kurstaki (Bt) ('NuCOTN 33B') cotton from 29 June to 11 August during 1997 and 1998. Deltapine 5415 bolls that accumulated 179 (7.2 d), 281 (11.2 d), and 253 (10.1 d) heat units beyond anthesis were safe from bollworm-induced abscission at 72 h after infestation, 7 d after infestation, and at the time of harvest, respectively. NuCOTN 33B bolls that accumulated 157 (6.3 d), 185 (7.4 d), and 180 (7.2 d) heat units beyond anthesis were safe from bollworm-induced abscission at 72 h after infestation, 7 d after infestation, and at the time of harvest, respectively. Bollworm larvae reduced seedcotton weights of Deltapine 5415 bolls that accumulated between 58.5 (2.3 d) and 350.5 (14.0 d) heat units beyond anthesis. Seedcotton weights of NuCOTN 33B bolls that accumulated between 0 and 281 (11.2 d) heat units beyond anthesis were reduced by bollworm injury. Deltapine 5415 and NuCOTN 33B bolls that accumulated 426.5 (17.1 d) and 299.5 (12.0 d) heat units beyond anthesis, respectively, before infestation were not injured by first-instar bollworm larvae. These data provide information about late-season insecticide termination strategies for bollworms on nontransgenic and transgenic Bt-cotton. This, in turn, will help pest managers determine when insecticides are no longer economical during the late season.

Ventricular volume, chamber stiffness, and function after anteroapical aneurysm plication in the sheep

OBJECTIVE

The success of left ventricular aneurysm plication depends on how the procedure affects both end-systolic elastance and diastolic compliance and how those changes affect ventricular function (stroke work/end-diastolic volume [PRSW] and stroke volume/end-diastolic pressure [Starling] relationships).

METHODS

Five male Dorsett sheep were surgically instrumented with coronary artery snares, an inferior vena caval occluder, and an ascending aortic ultrasonic flow probe. One week later an anteroapical myocardial infarction was produced by tightening the coronary snares. Ten weeks after myocardial infarction, the left ventricular aneurysm was plicated. Absolute left ventricular volume was measured by long-axis transdiaphragmatic echocardiography, and relative changes in left ventricular volume were measured with a conductance catheter. End-systolic elastance, diastolic compliance, PRSW, and Starling relationships were measured immediately before myocardial infarction, 10 weeks after myocardial infarction (immediately before plication), and immediately after and 6 weeks after aneurysm plication.

RESULTS

After plication, end-diastolic and end-systolic left ventricular volumes return to preinfarction values. The slopes of end-systolic elastance, diastolic compliance, and PRSW decrease 10 weeks after myocardial infarction, increase with aneurysm plication, and then decrease 6 weeks after aneurysm plication. The Starling relationship undergoes a downward parallel shift with aneurysm plication.

CONCLUSION

Aneurysm plication abruptly decreases left ventricular volume and diastolic compliance, increases end-systolic elastance and PRSW, but decreases the Starling relationship. The net effect on left ventricular function is mixed. Furthermore, left ventricular remodeling 6 weeks after aneurysm plication causes left ventricular volume, end-systolic elastance, diastolic compliance, PRSW, and the Starling relationship to return to preplication values.

Measurement of fibroblast proliferative activity in bronchoalveolar lavage fluid in the analysis of obliterative bronchiolitis among lung transplant recipients

BACKGROUND

Bronchiolitis obliterans occurs in 30% to 80% of lung-transplant recipients and is a direct cause of death in more than 40% of patients with this complication. This study assessed the potential utility of measuring fibroblast-proliferative activity in bronchoalveolar lavage fluid from lung-transplant recipients to better understand the pathogenesis of this process.

METHODS

The capacity of bronchoalveolar lavage fluid obtained from transplant recipients, during routine surveillance bronchoscopy, to stimulate the proliferation of human lung fibroblasts in vitro was assessed retrospectively and compared to that of control subjects. For each recipient, a correlation was made between the fibroblast-proliferative activity in serial lavage samples over time and the other modalities employed for detecting post-transplant complications including spirometry, transbronchial lung biopsy, and high-resolution computed tomography.

RESULTS

There was a significant difference in fibroblast-proliferative activity between volunteer and transplant recipient groups (p = 0.002). Further, for each transplant recipient, the decline in the forced expired flow rate between 25% and 75% of expired volume (FEF(25%-75%)) was correlated with the mean fibroblast-proliferative activity during the period of this study (r = 0.83; p = 0.04).

CONCLUSIONS

A sustained increase in fibroblast-proliferative activity in lavage supernatant precedes both histologic and physiologic evidence of bronchiolitis obliterans. Relative to an increase in fibroblast-proliferative activity or abnormalities in FEF25%-75%, a decrease in forced expiratory volume in 1 second is a late finding.

Mural left atrial thrombus: a hidden danger accompanying cardiac surgery

OBJECTIVE

To emphasize a potentially lethal condition that is virtually impossible to diagnose preoperatively.

DESIGN

Case report with review of the literature.

SETTING

University Hospital.

PARTICIPANT

The patient requiring urgent surgery for heart failure related to severe aortic stenosis and mild mitral stenosis with poor ventricular function. The patient was elderly and suffered from atrial fibrillation.

INTERVENTIONS

Preoperative transesophageal echocardiography followed by mitral valve repair and aortic valve replacement.

MEASUREMENTS

Clinical outcome and pathological results.

RESULTS

Although preoperative TEE demonstrated no left atrial appendage abnormality. After cardiac manipulation prior to the institution of cardiopulmonary bypass a large left atrial mural thrombus was mobilized from the atrial wall and was free floating in the left atrium.

CONCLUSIONS

For high risk patients TEE should be applied intraoperatively to avoid undiagnosed left atrial clot dislodgement.

Cardiac valve surgery in octogenarians: improving quality of life and functional status

BACKGROUND

Although cardiac valve procedures are being performed more frequently in the elderly, long-term functional outcomes have not been well characterized.

OBJECTIVE

To evaluate changes in quality of life and functional status in octogenarians after cardiac valve surgery.

DESIGN

Retrospective medical record review and patient telephone interview. Median follow-up 30 months (range, 6-95 months).

SETTING

Tertiary care university hospital.

PATIENTS

Octogenarians undergoing cardiac valve surgery (N = 61; mean age, 83.5 years; range, 80-89 years).

INTERVENTIONS

Forty-seven patients had aortic valve replacement, 14 had mitral valve replacement and/or repair, and 27 had a combined procedure with coronary artery bypass grafting.

OUTCOMES

Actuarial survival, morbidity, length of hospital stay, and discharge disposition were evaluated. Functional status, using the New York Heart Association classification, and Karnofsky performance status were evaluated preoperatively and postoperatively at 1 and 3 months after hospital discharge.

RESULTS

Operative (<30 days) mortality occurred in 7 (11.4%) of 61 patients. Preoperative intensive care unit stay (P < .001) and New York Heart Association class 4 (P < .02) were independent predictors of early death by multivariable analysis. Among hospital survivors, there were no major complications in 34 patients (63%), and this group had a mean (+/- SD) postoperative hospital stay of 12.2 +/- 5.5 days. Twenty patients (37%) incurred significant complications, the most common of which were bleeding, pneumonia, and renal insufficiency. The mean (+/- SD) postoperative hospital stay in this group was 25 +/- 17 days. Although significant complications were associated with an increased postoperative stay, this was not predictive of disposition to a skilled nursing facility or the final score on the postoperative Karnofsky performance scale. Actuarial survival was 85% at 1 year and 66% at 5 years. Patients with perioperative complications had significantly decreased actuarial survival by the Cox proportional hazards regression model (P < .001). Among hospital survivors, the score on the Karnofsky performance scale 1 month after discharge had improved 50% from a preoperative median score of 30% (severely disabled, requiring special care) to a postoperative median score of 80% (being able to perform normal activity with only moderate symptoms). The New York Heart Association classification improved a median of 2 classes in this group. These benefits were sustained at the 3-month follow-up.

CONCLUSION

Although greater resource expenditure is required for the initial perioperative convalescence, octogenarians can be expected to have an excellent functional outcome and long-term performance status after cardiac valve surgery.

Giant solitary fibrous tumor of the pleura

Solitary fibrous tumors of the pleura are rare. Approximately 600 cases have been described in the literature. We report a case of a young man with a giant solitary fibrous tumor of the pleura that filled his entire left hemithorax and anterior mediastinum and extended into the right side of his chest. The diagnostic modalities employed, the operation, and the postoperative management resulting in complete resection of the tumor and full lung reexpansion are described.

Retractor for coronary artery bypass grafting

A retractor is presented with features to enhance operative exposure for coronary artery bypass grafting while minimizing sternal and peripheral nerve injuries. The design is aimed at enhancing exposure while minimizing incision size.

Substernal goiter versus intrathoracic aberrant thyroid: a critical difference

A substernal goiter may descend into the thorax. However, a truly aberrant intrathoracic thyroid represents a rare and anatomically different entity that requires appropriate modifications in approach and surgical technique.

31P nuclear magnetic resonance determination of changes in energy state in lung preservation

The significance of dynamic changes in energy state during lung harvesting and preservation has not been extensively studied. Phosphorus 31 nuclear magnetic resonance spectra at 81 MHz were obtained from degassed rabbit lungs. Changes in the adenosine 5'-triphosphate-to-inorganic phosphate peak-intensity ratios were used to measure changes in energy state. Two groups of rabbit preparations were studied to evaluate the effect of hypothermia during the initial 120 minutes of harvesting (n = 8 at 36 degrees C and n = 5 at 4 degrees C). The significance of these changes was assessed in a second experiment in which lungs were reperfused in vitro at selected intervals of hypothermia (5, 12, and 24 hours) and assessed for injury. Hypothermic preservation sustained a significantly higher energy state. The depletion of energy state was correlated with injury, particularly as measured by lung edema (r2 = -0.715). Short periods of warm ischemia (30 minutes) result in a significant depletion of energy state, which may be a component of pulmonary injury during harvesting and preservation.

A critical review of the use of open lung biopsy in the management of the oncologic patient with acute pulmonary infiltrates

In a retrospective review, 28 open lung biopsies from 27 oncology patients with acute pulmonary infiltrates were evaluated. The operative complication rate was 28%, and the operative mortality 4%. Infection caused 57% of the infiltrates (16 cases); 87% of the infections were secondary to either Pneumocystis carinii or a viral infection. Two patients had bacterial pneumonia. Sixteen of these cases survived (37%). All but one survivor had Pneumocystis carinii. A nonspecific pneumonitis either with or without associated fibrosis caused 39% of the infiltrates (11 cases). Four of these patients survived (36%). Two patients had histologic evidence of residual tumor, one secondary to leukemia and the other to a lymphoma. One of these patients who also had Pneumocystis carinii survived. This study confirms the results of several other studies. Open lung biopsy in the oncology patient with an acute pulmonary infiltrate rarely establishes the presence of a treatable lesion other than Pneumocystis carinii, a diagnosis that can usually be established by bronchoscopy. The indications for open lung biopsy are therefore limited.

Successful four-hour heart-lung preservation with core-cooling on cardiopulmonary bypass: a simplified model that assesses preservation

This study was done to determine whether core-cooling could provide extended cardiopulmonary preservation and if reimplantation could be simulated and evaluated in the ex vivo autoperfused working heart-lung model. Twenty calves were divided into four groups and placed on cardiopulmonary bypass and rapidly cooled to 15 degrees C. Control heart and lungs were harvested after administration of cardioplegia through the aortic root and were subsequently resuscitated in the autoperfused working heart-lung circuit (group 1) or were orthotopically allotransplanted (group 2). Preserved heart and lungs were similarly excised but stored in a normal saline solution bath at 4 degrees C for 4 hours and then were resuscitated in the autoperfusion circuit (group 3) or were orthotopically allotransplanted (group 4). All groups received isoproterenol during explantation and reperfusion and were studied for 4 hours. Myocardial function was assessed by sonomicrometric techniques, and pulmonary preservation was evaluated by measurements of extravascular lung water, arterial oxygen tension on 100% inspired oxygen, and pulmonary vascular resistance. Cardiorespiratory function after 4-hour static preservation was similar in all four groups except that the arterial oxygen tension in group 1 was lower compared with group 3. Core-cooling on cardiopulmonary bypass without pulmonary artery flushing results in cold ischemic heart-lung preservation, comparable to other currently used modalities. In addition, reperfusion in the ex vivo autoperfusion circuit provides a simplified model to assess the adequacy of cardiopulmonary preservation techniques.

Diagnosis of acute cardiac rejection with antimyosin monoclonal antibody, phosphorous nuclear magnetic resonance imaging, two-dimensional echocardiography, and endocardial biopsy

A cervical heterotopic cardiac allograft model was used to compare noninvasive techniques with endocardial biopsy diagnosis of rejection. The transplant procedure was performed in eight dogs (12 to 16 kg), with a mean ischemic time of 83 minutes. Beginning on the day of the operation each allograft was evaluated daily by palpation, two-dimensional echocardiography, phosphorous nuclear magnetic resonance spectroscopy, and septal endocardial biopsy. At specific intervals after the operation, antimyosin monoclonal antibody (Fab fragment) with an indium-111 label was administered for subsequent gamma camera imaging. Rejection was clinically evident by 2 to 8 days with a mean of 3.5 days. Endocardial biopsy demonstrated moderate to severe rejection by 2 to 4 days. Two-dimensional echocardiography demonstrated early loss of wall thickening dynamics in all allografts. Although subtle changes were evident early in some transplants, these findings were not consistent. After recovery from hypothermic ischemia, evaluation of high energy phosphate metabolites with phosphorous nuclear magnetic resonance spectroscopy showed a progressive decrease in phosphocreatine during mild to moderate rejection, dropping to 30% to 40% of baseline levels with severe rejection. Antimyosin antibody uptake directly correlated with endocardial biopsy rejection scores (R2 = 0.97). With mild to moderate rejection, mean total counts and corrected counts were 222,704 and 112,648, respectively, and were significantly different (p less than 0.05) from baseline counts (135,537 and 58,530) without rejection. As a preliminary finding in untreated acute rejection, both antimyosin antibody and phosphorous nuclear magnetic spectroscopy detected changes consistent with mild to moderate rejection, which usually preceded echocardiographic evidence for injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Anatomic and anesthetic considerations in experimental cardiopulmonary surgery in swine

We have used immature commercial swine (13-25 kg) successfully in a variety of experimental cardiopulmonary surgical procedures in our laboratories since 1981. Multiple drug anesthetic protocols using barbiturates, narcotics, paralytic and antiarrhythmic agents have been employed in over 400 procedures per year. Complications, including fatal cardiac arrhythmias, have been greatly reduced by anesthetic protocols and surgical procedures developed through experience.

Differences in the pathogenesis of first-set allograft rejection and acute xenograft rejection as determined by sequential morphologic analysis

To examine the pathogenesis of unmodified heart xenograft and allograft rejection, a sequential morphologic analysis was undertaken. Heterotopic cardiac allografts and xenografts were performed by implanting donor hearts into the abdomen of Lewis rats. Xenograft donors were Golden Syrian hamsters and allograft donors were ACI rats. Both xenografts and allografts were excised and examined by light microscopy at specific postoperative intervals. Allograft rejection was found to be a cell-mediated process, beginning with interstitial infiltrates and perivascular cuffing, which progressed to focal myocyte necroses. Ultimately, complete replacement of the myocardium by mononuclear cells was noted in fully rejected hearts. Xenograft rejection was markedly different. Although xenograft rejection was characterized first by interstitial mononuclear cell infiltrates, unlike allografts there was only minimal progression of cellular rejection. Instead, subsequent rejection was characterized by marked interstitial edema and arteriolar vasculitis and thrombosis, leading to extensive infarcts and hemorrhage in fully rejected hearts. Fibrinoid arteriolar changes and the rapid development of edema in the absence of significant cellular infiltrate suggest that cytotoxic antibodies alter xenograft vascular permeability. These data suggest that humoral immunity is largely responsible for acute concordant xenograft rejection, whereas first-set allograft rejection is mainly a cell-mediated process.

Twenty-four hour lung preservation by hypothermia and leukocyte depletion

In lung preservation, as well as in other forms of pulmonary disease, injury is associated with sequestration of leukocytes. We hypothesized that leukocyte depletion could prevent reperfusion injury and prolong the period of safe lung preservation. The heart-lung block from 39 New Zealand white rabbits were harvested, flushed with 100 ml of a modified Collins solution, stored at 4 degrees C in a 30% inflation state, and reperfused with either whole blood or leukocyte depleted blood. Leukocyte depletion was accomplished using a blood filter and verified with selected leukocyte counts. Leukocyte readdition specimens were obtained from whole blood, the separation being done with hydroxyethyl starch and centrifugation at 4,000 rpm for five minutes. Six groups of rabbit lungs were studied. Group 1 consisted of control lungs that were not preserved and were reperfused with whole blood. Lungs in Group 2 underwent five-hour preservation and whole blood reperfusion. Lungs in Group 3 underwent five-hour preservation and leukocyte depleted blood reperfusion. Lungs in Group 4 underwent 24-hour preservation and leukocyte depleted blood reperfusion. Lungs in Group 5 also underwent 24-hour preservation, leukocyte depleted blood reperfusion, but with leukocyte readded at the onset of reperfusion. Lastly, lungs in Group 6 underwent 24-hour preservation, leukocyte depleted blood reperfusion, with leukocyte readdition after one hour of reperfusion. Group 5 showed pulmonary edema and complete reservoir emptying within the first hour of reperfusion. Group 2 had comparable poor results. Groups 3, 4, and 6 showed no significant differences from the control lungs in regard to pressure or reservoir loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemagglutination-inhibition test in rhinovirus infections of volunteers

The hemagglutination-inhibition (HI) test for antirhinovirus antibody was carried out on paired sera from volunteers inoculated with rhinovirus type 3 or type 4 (RV4). The HI test gave results which paralleled the neutralization test and was at least as sensitive as a microneutralization method for detection of serotype-specific antibody. Although high levels of HI antibody in the serum were associated with protection from infection, in the case of RV4 low serum HI antibody levels did not necessarily imply susceptibility to challenge with small doses of virus. HI activity could be measured in concentrated nasal-washing fluids, and this antibody also seemed relevant to protection against infection.

Use of recombination in the production of influenza vaccine strains

Recombination between influenza A viruses as a method of producing strains suitable for use in vaccines is discussed with particular reference to a recombination system involving an attentuated laboratory strain A/PR8/34 (HoN1) and a recent isolate of the epidemic strain A/Hong Kong/68 (H3N2). A variety of properties of the viruses were shown to be segregated independently of one another during recombination. These properties included the envelope antigens (haemagglutinin and neuraminidase), growth capacity in the fertile egg and attenuation for man. Some of the recombinants were considered suitable for use in vaccines either inactivated (whole virus particles or subunits) or live. The application of this technique to future requirements for vaccine strains are discussed with particular reference to the safety aspect of using recombinants in live vaccines.

Trial of the antiviral action of isoprinosine against rhinovirus infection of volunteers

Isoprinosine (NPT-10381) was given orally to a group of 22 volunteers at a daily dose of 6 g for 7 days; a control group of 23 volunteers received placebo. Volunteers were inoculated intranasally with both rhinovirus type 9 and rhinovirus type 31, and the clinical picture, extent of virus shedding, and serological responses were assessed. There was no evidence that the compound had useful antiviral activity under the conditions of this trial.

A virus from epidemic vomiting disease

An illness consisting of vomiting, fever, and mild diarrhoea after a short incubation period was observed in a boarding school and reproduced in volunteers who received filtered extracts of faeces from a typical case. The main discriminatory diagnostic feature of the illness in volunteers was vomiting. The faeces contained no pathogenic bacteria nor any virus that could be detected in tissue cultures and there was no evidence that an infective agent could be grown in organ cultures of human intestine. The agent was shown to be ether stable and passed a 50-nm filter. Laboratory studies on another agent of uncertain significance and obtained in other epidemics are briefly described.

Experimental infection of human volunteers with a swine influenzavirus antigenically related to the human A-Hong Kong-68 virus

An influenzavirus of swine origin (swine/Taiwan/7310/70) antigenically closely related to the human A/Hong Kong/68 virus readily infected human volunteers. Those infected developed antihaemagglutinin and antineuraminidase antibodies to the human A/Hong Kong/68 virus as well as to the swine/Taiwan virus. The clinical reactions produced by the swine/Taiwan virus were, however, milder than those produced in volunteers infected with A/Hong Kong/68. In contrast, two other "classical" swine viruses (strains antigenically related to the prototype swine/Iowa/15/30 strain), immunologically distinct from the Hong Kong/68 virus, possessed low infectivity for man.

Recombinant influenza-A viruses as live vaccines for man. Report to the Medical Research Council's Committee on Influenza and other Respiratory Virus Vaccines

The infection of volunteers with five hybrid influenza-A viruses is described. Four of these were produced in Great Britain by recombining an Ao virus, non-infective for man, with a wild Hong Kong like strain. The fifth was the American recombinant, X-31, derived from similar parents and widely used in the manufacture of killed vaccines. All five viruses had the haemagglutinin and neuraminidase of A2/Hong Kong/68. Two of the viruses were not attenuated and induced symptoms of clinical influenza. The other three were appreciably attenuated and were infective and antigenic. It seems that recombination is a rapid and effective way of producing live vaccine viruses to specification. It is also the quickest known method of attenuation.

A comparative study of attenuated influenza viruses

Influenza A and influenza B viruses were adapted to growth at 25 degrees C. When given to volunteer subjects, the viruses were attenuated but remained infective and antigenic. The minimum immunizing dose of an egg-adapted virus appeared to be 10(5.0) EID(50). Cloning by plaque selection at 25 degrees C gave seed cultures of relatively low infectivity titres. These titres were increased when necessary by passage at 33 degrees C. No reversion to virulence was observed.Viruses attenuated in the United Kingdom and the USA were compared in volunteer trials with vaccine strains that had already been used in the USSR for mass immunization. Results were broadly similar. Currently available methods of attenuation and work with temperature-sensitive mutants are reviewed.