Cardiovascular complications of severe acute respiratory syndrome.

BACKGROUND AND AIMS: Severe acute respiratory syndrome (SARS) is a virulent viral infection that affects a number of organs and systems. This study examined if SARS may result in cardiovascular complications. METHODS AND RESULTS: 121 patients (37.5 (SD13.2) years, 36% male) diagnosed to have SARS were assessed continuously for blood pressure, pulse, and temperature during their stay in hospital. Hypotension occurred in 61 (50.4%) patients in hospital, and was found in 28.1%, 21.5%, and 14.8% of patients during the first, second, and third week, respectively. Only one patient who had transient echocardiographic evidence of impaired left ventricular systolic function required temporary inotropic support. Tachycardia was present in 87 (71.9%) patients, and was found in 62.8%, 45.4%, and 35.5% of patients from the first to third week. It occurred independent of hypotension, and could not be explained by the presence of fever. Tachycardia was also present in 38.8% of patients at follow up. Bradycardia only occurred in 18 (14.9%) patients as a transient event. Reversible cardiomegaly was reported in 13 (10.7%) patients, but without clinical evidence of heart failure. Transient atrial fibrillation was present in one patient. Corticosteroid therapy was weakly associated with tachycardia during the second (chi(2) = 3.99, p = 0.046) and third week (chi(2) = 6.53, p = 0.01), although it could not explain tachycardia during follow up. CONCLUSIONS: In patients with SARS, cardiovascular complications including hypotension and tachycardia were common but usually self limiting. Bradycardia and cardiomegaly were less common, while cardiac arrhythmia was rare. However, only tachycardia persisted even when corticosteroid therapy was withdrawn.

A simple score for predicting coronary artery disease in patients with chest pain.

BACKGROUND: We have previously derived a chest pain score by comparing those with and without coronary artery disease on angiography, which was subsequently validated in patients attending coronary angiography. AIM: To test the predictive validity of the score prospectively in a more varied out-patient population, and to determine whether it had predictive validity in addition to exercise testing. DESIGN: Prospective clinical study. METHODS: The score was applied to 405 out-patients with chest pain who subsequently underwent coronary angiography. Framingham risk analysis and exercise testing were performed in 155. RESULTS: The score had a sensitivity of 91.4% and specificity of 28% for coronary artery disease, which was found in 31.8%, 51%, 63%, and 82% of those with scores of 0, 1, 2, and 3, respectively. Gender (p < 0.001), age (p < 0.001), and chest pain score (p = 0.009) independently predicted coronary artery disease on multivariate Poisson regression analysis. The chest pain score had additive predictive value with Framingham risk analysis and Duke's score. DISCUSSION: This simple chest pain score can predict coronary anatomy with similar sensitivity to exercise testing, and can be used in conjunction with exercise testing and other measures. Further validation of the chest pain score in the primary care setting will be useful.

Plasma sialic acid and coronary artery atheromatous load in patients with stable chest pain.

Serum or plasma sialic acid and C-reactive protein have recently been shown to be cardiovascular risk factors. Our aim was to determine whether plasma sialic acid or C-reactive protein concentration correlate with atheromatous load on coronary angiography. Plasma sialic acid concentration and plasma C-reactive protein concentration were determined in 128 consecutive patients attending day case coronary angiography. Patients were excluded for previous coronary angioplasty, coronary artery bypass grafting, recent myocardial infarction, acute or chronic inflammatory disease and proximal occlusions precluding analysis of distal coronary anatomy. Total cholesterol, triglyceride, HDL cholesterol and glucose concentrations were assayed on fasting samples of venous blood. Angiograms were graded according to a semisubjective scoring system. There was no significant correlation between plasma sialic acid (r = 0.19, P = 0.07), or C-reactive protein concentration (r = 0.17, P = 0.13) and atheromatous load. There was no significant correlation between sialic acid (P = 0.13), or C-reactive protein concentration (P = 0.32) and the number of diseased coronary vessels. The difference in plasma sialic acid concentration between those with normal coronary angiograms and those with coronary artery disease did not reach significance (P = 0.08). Plasma sialic acid concentration correlated with C-reactive protein (r = 0.58, P = 0.0001), serum triglyceride (r = 0.32, P = 0.002), and blood cholesterol concentration (r = 0.22, P = 0.04). Plasma sialic acid concentration does not correlate with atheromatous load on coronary angiography in patients with stable angina.

A chest pain score for stratifying the risk of coronary artery disease in patients having day case coronary angiography.

'Typical' or 'atypical' are universally used descriptions of chest pain, but they are limited by subjectivity. This study tested the ability of a semi-objective chest pain score to predict the likelihood of coronary disease. A chest pain questionnaire was given to 250 patients with stable chest pain attending coronary angiography. The answers to three questions were defined as 'typical' or 'atypical' and summed to give a 'typical' score between 0 and 3. Logit analysis was performed based on an age cut-off of 55 years and 'typical' score. There were 96 (38%) patients with normal coronary arteries and 154 (62%) with coronary disease. In patients aged under 55 years, the likelihood of coronary disease by 'typical' score was 11% (score 0), 30% (score 1), 40% (score 2), 53% (score 3). Similar figures for age 55 years were 39% (score 0), 45% (score 1), 77% (score 2), and 85% (score 3). There is a direct relationship between 'typical' chest pain score and the likelihood of coronary artery disease. This scoring system may be useful in the clinical characterization of patients for research, for guiding referral to a cardiologist or for aiding the decision to perform coronary angiography.

The role of transesophageal echocardiography in patients with chronic renal failure at low and high risk of endocarditis.

BACKGROUND AND AIMS OF THE STUDY: The benefits of transesophageal echocardiography (TEE) may depend on the clinical likelihood of infective endocarditis, but little data exist on patients at low risk. METHODS AND RESULTS: We studied 32 patients with renal failure with either a low (n = 21) or high (n = 11) level of clinical suspicion for infective endocarditis. In the low-risk cases, TEE provided no new information whether the transthoracic echo was normal or abnormal, although it did confirm that an echogenic mass was more likely to be a calcific deposit than a vegetation. In the high-risk cases, transthoracic echocardiography was always abnormal but TEE added new information in seven out of 11 cases-positively in six, and by exclusion in one. TEE detected signs of complications of infective endocarditis in one case. CONCLUSIONS: We conclude that, when the clinical suspicion of endocarditis is low, TEE is rarely necessary.

Protective effects of MCI-186 on transplantation of bone marrow stromal cells in rat ischemic stroke model.

Transplantation of bone marrow stromal cells (BMSCs) is a potential therapy for ischemic stroke, but poor environmental conditions in brain lesions, such as insufficient nutrition and oxygen free radical toxicity, limit the efficacy of stem cell therapy. Here, we hypothesized that MCI-186, a free radical scavenger, would have protective effects on transplantation of BMSCs in a rat ischemia model. In vitro, flow cytometry showed the apoptotic rates of BMSCs after simulated ischemia-reperfusion (I/R) injury was significantly decreased when treated with MCI-186 (P<0.01). In vivo, rat transient middle cerebral artery occlusion (MCAO) model was established. Two separate MCAO groups were administered with either MCI-186 or phosphate-buffered solution (PBS) immediately after artery occlusion. MCI-186 significantly up-regulated the secretion of brain-derived neurotrophic factor, vascular endothelial growth factor and superoxide dismutase in ischemic brain, while malondialdehyde decreased and neuronal apoptosis was inhibited. Furthermore, another four MCAO groups were administered with either PBS, MCI-186, BMSCs (2×10(6)) or a combination of MCI-186 and BMSCs. When compared with BMSCs or MCI-186 monotherapy, combination therapy significantly improved functional restoration, decreased infarct volume, and increased the number of engrafted-BMSCs and neurons in ischemic brain. The number of engrafted-BMSCs and neurons was significantly correlated with functional outcomes. This study suggests that MCI-186 may improve the environment of the injured brain, enhance the survival of engrafted-BMSCs and neurotization in ischemic brain and produce protective effects on BMSCs transplantation.

Improvement of left ventricular myocardial short-axis, but not long-axis function or torsion after cardiac resynchronisation therapy: an assessment by two-dimensional speckle tracking.

AIMS: To evaluate whether short-axis function plays a part in determining left ventricular (LV) geometric and functional improvement after cardiac resynchronisation therapy (CRT). METHODS AND RESULTS: 39 patients who received CRT were enrolled. 2D speckle tracking echocardiography was performed at baseline and three months after CRT to assess mean systolic circumferential (epsilon-circum), radial (epsilon-radial) and longitudinal (epsilon-long) strain and torsion. Responders of reverse remodelling (n = 21) had higher baseline mean epsilon-circum than non-responders (p<0.05), who also had improvement in mean epsilon-circum and mean epsilon-radial (both p<0.05) after CRT. Also, the increase in mean epsilon-circum correlated with increase in ejection fraction (r = 0.57, p<0.001) and decrease in mid-cavity width (r = -0.52, p = 0.001). A baseline mean epsilon-circum of >or=6.5% predicted a gain in ejection fraction >or=5%, with a sensitivity of 73% and a specificity of 71%. The baseline epsilon-long was not different between the two groups, and remained unchanged after CRT. The torsion did not improve in responders, but was worsened in non-responders (p<0.05). CONCLUSIONS: The improvement of LV short-axis function but not long-axis function or torsion contributes to the improvement in LV global function and geometry at three-month follow up. A relatively preserved mean epsilon-circum of >or=6.5% might be useful to predict favourable responses after CRT.

A review of the management of patients after percutaneous coronary intervention.

The exponential increase in the numbers of percutaneous coronary interventions (PCIs) has led to many clinicians having to care for post-PCI patients. We review the management of early problems seen in post-PCI patients, such as vascular access site complications, contrast nephropathy, drug-induced thrombocytopaenia and chest pain. The management of possible restenosis and the use of stress testing are discussed. The complications from dual antiplatelet therapy are addressed. The prognosis of the post-PCI patient, the implications of co-existent heart failure and the newer technologies of implantable defibrillator and cardiac resynchronisation therapy are reviewed. We conclude by emphasising the importance of secondary prevention by risk factor modification as well as the communication between the clinician and the cardiologist.

Tissue Doppler velocity is superior to displacement and strain mapping in predicting left ventricular reverse remodelling response after cardiac resynchronisation therapy.

OBJECTIVE: To compare the values of three different forms of tissue Doppler imaging (TDI) processing in predicting left ventricular (LV) reverse remodelling-namely, tissue velocity, displacement and strain mapping. DESIGN: Standard echocardiography with TDI was performed before and 3 months after cardiac resynchronisation therapy (CRT). SETTING: University teaching hospital. PATIENTS: 55 patients with heart failure who received CRT and were followed up for at least 3 months were recruited. INTERVENTIONS: During off-line analysis, the time to peak systolic velocity in the ejection phase, time to peak positive displacement and time to peak negative strain were measured in the six basal, six mid-segmental model. Parameters of systolic asynchrony derived by velocity, displacement and strain mapping were correlated with percentage reduction in LV end systolic volume (LVESV) and absolute gain in ejection fraction (EF). RESULTS: Among the three TDI processing technologies, all parameters of tissue velocity correlated with LV reverse remodelling (r = -0.49 to r = -0.76, all p < 0.001), but the predictive value was strongest in models with 12 LV segments. For displacement mapping, only the two parameters that included 12 LV segments correlated modestly with reduction in LVESV (r = -0.36, p < 0.05) and gain in EF. However, none of the strain mapping parameters predicted a favourable echocardiographic response. The receiver operating characteristic (ROC) curve areas were higher for parameters of tissue velocity based on 12 LV segments (ROC areas 0.88 and 0.94) than the corresponding areas derived from displacement mapping (ROC areas 0.72 and 0.71). CONCLUSION: Tissue velocity parameters of systolic asynchrony are superior to those of displacement and strain mapping in predicting LV reverse remodelling response after CRT.

Management of diastolic heart failure--a practical review of pathophysiology and treatment trial data.

The lack of large randomised controlled trials to guide therapy in diastolic heart failure causes some difficulties for evidence-based medicine practising clinicians. Traditionally, treatments for systolic heart failure have been highjacked for diastolic heart failure without much proof of benefit. However, recent studies have began to provide some evidence base for our practice. Betablockers and angiotensin receptor antagonists have recently been shown to reduce hospitalisation in large randomised controlled trials. Diuretic based antihypertensive regimes have been shown to reduce heart failure by 50%. Left ventricular hypertrophy regression is likely to be a good surrogate endpoint for diastolic heart failure, although definitive proof for this is not yet available. Angiotensin receptor antagonists, ACEI, calcium channel blockers, diuretics and aldosterone blockers have all been shown to cause left ventricular hypertrophy regression. We recommend these drugs to achieve strict blood pressure control together with dietary and lifestyle modification for the treatment of diastolic heart failure. We emphasise the importance of rate control, as diastolic heart-failure patients tolerate tachycardia poorly. We further argue that the pathophysiology of diastolic heart failure is part of systolic heart failure and the two should not be thought of as separate entities. Therefore, our traditional practice of using systolic heart failure treatments for diastolic heart failure is theoretically sound and should not cause us undue anxiety.

Reversible cardiomyopathy after radiofrequency ablation of lateral free-wall pathway-mediated incessant supraventricular tachycardia.

Incessant supraventricular tachycardia leading to reversible cardiomyopathy has been reported. Cardiomyopathy usually only develops after prolonged episodes of tachycardia at a significant heart rate. Left ventricular free-wall pathways rarely cause fast and incessant tachycardia. Therefore cardiomyopathy has not been reported with left ventricular free-wall pathway-mediated supraventricular tachycardia. We report on two cases of left ventricular free-wall-mediated supraventricular tachycardia leading to reversible cardiomyopathy after radiofrequency ablation. These cases illustrate the difficulty in diagnosing tachycardia-mediated cardiomyopathy, as the tachycardia may be clinically silent. In addition, they emphasize the importance of making this diagnosis, as the cardiomyopathy is reversible.