Role of the 12-lead electrocardiogram in diagnosing pulmonary embolism

We investigated the role of the standard 12-lead electrocardiogram (ECG) to improve the pretest probability of pulmonary embolism before performing computed tomographic (CT) pulmonary angiography. A retrospective chart analysis was performed on patients who underwent CT pulmonary angiography at a tertiary care hospital during a 30-month period. Comparison of 15 ECG parameters was made between those with CT pulmonary angiograms positive for pulmonary embolism and a matched control group with negative CT pulmonary angiograms. Data were analyzed by chi-squared tests and logistic regression. Sinus tachycardia (39% vs. 24%, P <0.01), an S1 Q3 T3 pattern (12% vs. 3%, P <0.01), atrial tachyarrhythmias (15% vs. 4%, P <0.005), a Q wave in lead III (40% vs. 26%, P <0.02), and a Q3 T3 pattern (8% vs. 1%, P <0.02) were the findings significantly associated with pulmonary embolism. We conclude that 1) standard 12-lead ECG findings can increase the pretest probability of pulmonary embolism before performing CT pulmonary angiography; and that 2) the ECG findings have relatively low likelihood ratios to have clinical use.     

Thrombopoietin primes human platelet aggregation induced by shear stress and by multiple agonists

Recombinant thrombopoietin has been reported to stimulate megakaryocytopoiesis and thrombopoiesis and it may be quite useful to treat patients with low platelet counts after chemotherapy. As little is known regarding the possible activation of platelets by thrombopoietin, we examined the effects of thrombopoietin on platelet aggregation induced by shear stress and various agonists in native plasma. Using hirudin as an anticoagulant, thrombopoietin (1 to 100 ng/mL) enhanced platelet aggregation induced by 2 micromol/L adenosine- diphosphate (ADP) in a dose dependent fashion. The enhancement was not affected by treatment of platelets with 1 mmol/L aspirin plus SQ-29548 (a thromboxane antagonist, 1 micromol/L) but was inhibited by a soluble form of the thrombopoietin receptor, suggesting that the enhancement was mediated by the specific receptors and does not require thromboxane production. Epinephrine (1 micromol/L), which does not induce platelet aggregation in hirudin platelet rich plasma (PRP), did so in the presence of thrombopoietin (10 ng/mL). Thrombopoietin (10 ng/mL) also enhanced or primed platelet aggregation induced by collagen (0.5 micron.mL),. thrombin, serotonin, and vasopressin. Thrombopoietin does not induce any rise in cytosolic ionized calcium concentration nor activation of protein kinase C, as estimated by phosphorylation of preckstrin, indicating that the priming effects of thrombopoietin does not require those processes. The ADP- or thrombin-induced rise in cytosolic ionized calcium concentration was not enhanced by thrombopoietin (100 ng/mL). Further, shear (ca. 90 dyn/cm2)-induced platelet aggregation was also potentiated by thrombopoietin. The priming effect on epinephrine-induced platelet aggregation in hirudin PRP was unique to thrombopoietin, with no effects seen using interleukin-6 (IL-6), IL-11, IL-3, erythropoietin, granulocyte-colony stimulating factor, granulocyte macrophage-colony stimulating factor, or c-kit ligand. These data indicate that monitoring of platelet functions may be necessary in the clinical trials of thrombopoietin.     

Inhibition of endotoxin-induced activation of the coagulation and fibrinolytic pathways using a recombinant endotoxin-binding protein (rBPI23)

A recombinant endotoxin-neutralizing protein, rBPI23, was shown to partially prevent endotoxin-induced activation of the fibrinolytic and coagulation systems in experimental endotoxemia in humans. In a placebo- controlled, blinded crossover study, eight volunteers were challenged twice with an intravenous bolus injection of endotoxin (40 EU/kg of body weight) and concurrently received either rBPI23 (1 mg/kg) or placebo (human serum albumin, 0.2 mg/kg). rBPI23 treatment significantly lowered the endotoxin-induced fibrinolytic response, ie, reduced the release of tissue-type plasminogen activator, urokinase- type plasminogen activator, plasminogen activator inhibitor antigen, and complex formation of plasmin alpha 2-antiplasmin (P = .0078 for each). Plasminogen activator inhibitor activity was also reduced, but not significantly according to the Hochberg method (P = .0304). The endotoxin-induced activation of the procoagulant state as reflected by increase in F1 + 2 fragments and TAT complexes was blunted by rBPI23 infusion (P = .0391 [not significant according to the Hochberg method] and .0078, respectively). These results indicate that rBPI23 is capable of reducing both the activation of the fibrinolytic and the coagulation systems after low-dose endotoxin infusion in humans.     

Stress myocardial imaging in patients with mitral valve prolapse: Evidence of a perfusion abnormality

Twenty-four patients with mitral valve prolapse underwent cardiac catheterization, exercise testing, and exercise ²⁰¹thallium scintigraphy. Of 10 patients with coronary artery disease, six had abnormal scintigrams. Two of these six had exercise-induced reversible defects, two had defects that persisted during redistribution, and two had both reversible and persistent defects. Of 14 patients with normal coronary arteries, five had negative scintigrams. Of the remaining nine patients, two had exercise-induced defects, and seven (50%) had defects involving the inferior or posterior wall that persisted during redistribution. Possible mechanisms for this latter finding are discussed. In contrast to previous reports, exercise ²⁰¹thallium scintigraphy was not entirely successful in identifying patients with coronary artery disease in our patients with mitral valve prolapse.     

Older age should not be a barrier to the treatment of hypertension

Commentaries and debates at national medical meetings have fuelled the controversy about treatment of hypertension in patients aged 80 years and older. A double-blind, randomized, placebo-controlled trial was, therefore, indicated to settle the dispute about whether antihypertensive drug therapy is efficacious or harmful in these patients. Results from HYVET (Hypertension in the Very Elderly Trial) showed that, at 2-year follow-up, antihypertensive drug therapy with indapamide, plus perindopril if needed, reduced fatal or nonfatal stroke by 30%, fatal stroke by 39%, all-cause mortality by 21%, cardiovascular death by 23%, and heart failure by 64%. These results indicate that hypertensive patients aged 80 years and older should be treated with antihypertensive drugs.     

Quality of care of nursing home residents hospitalized with heart failure

OBJECTIVES: To determine whether the quality of heart failure (HF) care of hospitalized nursing home (NH) residents is different from that of patients admitted from other locations. DESIGN: Retrospective chart review. SETTING: Nursing home residents discharged from hospitals. PARTICIPANTS: Medicare beneficiaries aged 65 and older. MEASUREMENTS: Subjects were discharged with a primary discharge diagnosis of HF in Alabama in 1994. They were categorized as having been admitted from a NH or other locations. Bivariate logistic regression analysis was used to estimate crude odds ratios (ORs) and 95% confidence intervals (CIs) for left ventricular function (LVF) evaluation and angiotensin-converting enzyme (ACE) inhibitor use for NH residents relative to nonresidents. Multivariate generalized linear models were developed to determine independence of associations. RESULTS: Subjects (N = 1,067 years) had a mean age +/- standard deviation of 79 +/- 7.4, 60% were female, and 18% were African Americans. Fewer NH residents (n = 95) received LVF evaluation (39% vs 60%, P <.001) and ACE inhibitors (50% vs 72%, P =.111). NH residents had lower odds for LVF evaluation (OR = 0.42, 95% CI = 0.27-0.64). The odds for ACE inhibitor use, although of similar magnitude, did not reach statistical significance (OR = 0.40, 95% CI = 0.12-1.28). After adjustment of patient and care characteristics, admission from a NH was significantly associated with lower LVF evaluation (adjusted OR = 0.64, 95% CI = 0.49-0.82) but not with ACE inhibitor use (adjusted OR = 0.59, 95% CI = 0.16-2.14). CONCLUSIONS: Quality of HF care received by hospitalized NH residents was lower than that received by others. Further studies are needed to determine reasons for the lack of appropriate evaluation and treatment of NH patients with HF who are admitted to hospitals.     

Inpatient telemetry does not need to be used in the management of older patients hospitalized with chest pain at low risk for in-hospital coronary events and mortality

BACKGROUND: Little is known about patients admitted with chest pain to inpatient telemetry units directly from an emergency department. METHODS: We analyzed data from 105 consecutive patients who presented with chest pain to an emergency department and who were hospitalized in an inpatient telemetry unit but who were at low risk for a coronary event. RESULTS: Telemetry yielded no information which was used to manage any patient. None of the 105 patients (0%) developed a myocardial infarction or died during hospitalization. At 4.8-year follow-up, 8 of 105 patients (8%) died. Significant risk factors for long-term mortality were age (p < .001), prior coronary artery disease (p < .05), and diabetes (p < .02). CONCLUSIONS: Inpatient telemetry was of no value in predicting short-term coronary events or mortality or long-term mortality in low-risk patients hospitalized with chest pain.     

Effect of simvastatin versus placebo on treadmill exercise time until the onset of intermittent claudication in older patients with peripheral arterial disease at six months and at one year after treatment

Simvastatin significantly increased treadmill exercise time until onset of intermittent claudication from baseline by 54 seconds (a 24% increase, p <0.0001) at 6 months after treatment and by 95 seconds (a 42% increase, p <0.0001) at 1 year after treatment. At 6 months and 1 year after treatment with placebo, treadmill exercise time until onset of intermittent claudication was not significantly different from baseline exercise time.     

Prevalence of symptomatic peripheral arterial disease, modifiable risk factors, and appropriate use of drugs in the treatment of peripheral arterial disease in older persons seen in a university general medicine clinic

BACKGROUND: Persons with peripheral arterial disease (PAD) have a high incidence of cardiovascular morbidity and mortality. METHODS: We investigated the prevalence of symptomatic PAD, modifiable risk factors, and use of drugs in persons 60 years and older seen in a university general medicine clinic. Symptomatic PAD was documented if the person had a documented history of surgery for PAD, if the person had intermittent claudication or other lower extremity symptoms associated with absent or weak arterial pulses or an ankle-brachial index of <0.90, if the person had an abdominal aortic aneurysm, or if the person had symptomatic documented extracranial carotid arterial disease. RESULTS: There were 620 women and 386 men, mean age 72+/-9 years (range 60-95 years), and 95% were white. Symptomatic PAD was present in 103 of 386 men (27%) and in 106 of 620 women (17%) (p<.001). The prevalence of current cigarette smoking (31% versus 12% in those without PAD, p<.001) and ex-cigarette smoking (40% versus 26%) in those without PAD, p<.001) was higher among persons with PAD. Compared with persons without PAD, those with PAD also had a higher prevalence of hypertension (90% versus 76% in persons without PAD, p<.001), diabetes mellitus (45% versus 22%, p<.001), dyslipidemia (88% versus 60%, p<.001), coronary artery disease (63% versus 25%, p<.001), and stroke (36% versus 11%, p<.001). In persons with PAD, antiplatelet drugs were used in 85%, lipid-lowering drugs for dyslipidemia in 67%, beta blockers in 60%, and angiotensin-converting enzyme (ACE) inhibitors or angiotensin-receptor blockers in 62%. The average of the last two blood pressures was <140/90 mmHg in 55% of persons with PAD treated for hypertension. The last hemoglobin A1c in diabetics was <7% in 52% of persons with PAD. CONCLUSIONS: Older persons with PAD have a high prevalence of modifiable risk factors, CAD, and stroke. The use of antiplatelet drugs, lipid-lowering drugs for dyslipidemia, beta blockers, and ACE inhibitors or angiotensin-receptor blockers, reduction of blood pressure to <140/90 mmHg in hypertensive persons, and reduction of hemoglobin A1c in diabetics to <7% in older persons with PAD needs to be increased in all clinical settings.     

Comparison of outcomes in patients with active infective endocarditis and a paravalvular abscess on a prosthetic valve versus a native valve

We investigated in-hospital and long-term mortality in 16 patients with infective endocarditis and paravalvular abscess on a prosthetic valve (6 of whom underwent surgery) and in 12 patients with infective endocarditis and paravalvular abscess on a native valve (8 of whom underwent surgery). The only significant risk factor for in-hospital mortality in patients with prosthetic or native value paravalvular abscess was age (P < 0.001). In-hospital mortality was 33% in patients with prosthetic valve paravalvular abscess undergoing surgery and 33% in patients treated medically (P = not significant). In-hospital mortality was 25% in patients with native valve paravalvular abscess undergoing surgery and 25% in patients treated medically (P = not significant). At 4.8-year follow up, survival of patients with prosthetic valve paravalvular abscess was 67% for patients treated surgically versus 40% for patients treated medically (P = not significant). At 4.8-year follow up, survival of patients with native valve paravalvular abscess was 75% for patients treated surgically versus 50% for patients treated medically (P = not significant).