Sven V. Eriksson

RELIABILITY AND RESPONSIVENESS OF THREE DIFFERENT PAIN ASSESSMENTS

The visual analogue scale (VAS) and ordered categorical scales, i.e. numeric rating scales (NRS), are commonly used in the assessment of pain. However, these scales are bounded by fixed endpoints and thus the range of measurement is limited. The disparity in repeated assessments of perceived pain intensity with the VAS, NRS, and electrical stimulation applied as a matching stimulus was studied in 69 patients (48 women and 21 men, 19-72 years) with chronic nociceptive or neurogenic pain. Responsiveness with transcutaneous electrical nerve stimulation (TENS) using the same measurement procedures was evaluated in the same patients. Comparison of results from the three pain assessments showed that the painmatcher is at least as reliable and responsive as VAS and NRS. None of the three measurements showed evidence for systematic disagreement and had only significant random individual disagreement. They also showed evidence for responsiveness.

Favourable long term prognosis in stable angina pectoris: an extended follow up of the angina prognosis study in Stockholm (APSIS)

Objective: To evaluate the long term prognosis of patients with stable angina pectoris. Design: Registry based follow up (median 9.1 years) of patients participating in the APSIS (angina prognosis study in Stockholm), which was a double blind, single centre trial of antianginal drug treatment. Patients: 809 patients (31% women) with stable angina pectoris < 70 (mean (SD) 59 (7) years at inclusion) and an age and sex matched reference population from the same catchment area. Interventions: Double blind treatment with metoprolol or verapamil during 3.4 years (median), followed by referral for usual care with open treatment. Main outcome measures: Cardiovascular (CV) death and non-fatal myocardial infarction (MI) in the APSIS cohort and total mortality in comparison with reference subjects. Results: 123 patients died (41 MI, 36 other CV causes) and 72 had non-fatal MI. Mortality (19% v 6%, p<0.001) and fatal MI (6.6% v 1.6%, p < 0.001) were increased among male compared with female patients. Diabetes, previous MI, hypertension, and male sex independently predicted CV mortality (p < 0.001). Diabetes greatly increased the risk in a small subgroup of female patients. Male patients had higher mortality than men in the reference population during the first three years (cumulative absolute difference 3.8%) but apparently not thereafter. Female patients had similar mortality to women in the reference population throughout the 9.1 years of observation. Conclusions: Female patients with stable angina had similar mortality to matched female reference subjects but male patients had an increased risk. Diabetes, previous MI, hypertension, and male sex were strong risk factors for CV death or MI.

Prognostic information from on-line vectorcardiography in acute myocardial infarction

The present study assesses the prognostic information from continuous on-line vectorcardiography in patients with acute myocardial infarction (AMI). A series of 203 patients with AMI were studied. Vectorcardiographic (VCG) recordings were obtained continuously for 24 hours. Analysis was performed on-line with the commercial system MIDA CoroNet. QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM), and ST vector magnitude (ST-VM) were monitored. Patients were followed for 538 +/- 220 days. During follow-up, 36 patients died from cardiac causes and 38 patients had reinfarction. A significantly higher occurrence of transient VCG changes (QRS-VD, STC-VM, and ST-VM; p < 0.001) was seen in patients who died from cardiac causes or experienced either cardiac death or reinfarction at follow-up. The end value for QRS-VD was higher in patients who died from cardiac causes and correlated with the maximal value for creatine kinase when all patients were considered (r = 0.66; p < 0.001). Significantly lower mortality was seen in patients with VCG trend curves suggestive of coronary reperfusion (p < 0.01). In multivariate analysis, occurrence of transient changes in STC-VM, high QRS-VD end value, and VCG trend curves not suggestive of reperfusion gave additional prognostic information beyond that of age, gender, maximal creatine kinase value, heart size on chest x-ray, occurrence of ventricular fibrillation during hospitalization, and the inability to perform exercise tests. VCG monitoring during the first 24 hours of hospitalization for an AMI is a promising method for early detection of patients with increased risk for subsequent cardiac death or reinfarction.

Neurohormonal activation in heart failure after acute myocardial infarction treated with beta-receptor antagonists

Few studies have described how neurohormonal activation is influenced by treatment with beta‐receptor antagonists in patients with heart failure after acute myocardial infarction. The aims were to describe neurohormonal activity in relation to other variables and to investigate treatment effects of a beta1 receptor‐antagonist compared to a partial beta1 receptor‐agonist.

Continuous Vectorcardiography in Patients with Chest Pain Indicative of Acute Ischemic Heart Disease

To assess the clinical usefulness of continuous on-line vectorcardiography (VCG), we studied 61 patients admitted to the coronary care unit (CCU) with chest pain, supposedly ischemic. Continuous VCG was performed for 24 h, monitoring QRS vector difference (QRS-VD), ST-change vector magnitude (STC-VM) and ST vector magnitude (ST-VM) measured 20 and 60 ms after the termination of the QRS complex. The patients were divided into four groups based on the final diagnosis; group A, 15 patients with normal exercise tests and extracardiac causes of chest pain; group B, 15 patients with unstable angina; group C, 15 patients with non-Q-wave myocardial infarction (MI); group D, 16 patients with Q-wave MI. Treatment was given according to a normal routine. Of 31 patients with MI, 16 received treatment with streptokinase. Groups A and B showed no significant permanent changes in QRS-VD, STC-VM or ST-VM. However, group B showed a higher occurrence of transient episodes (duration: 2 min-6 h) of a significant change of QRS-VD by > 15 microVs and of STC-VM, ST-VM 20 and ST-VM 60 by > 0.1 mV. Groups C and D showed both permanent changes and transient episodes for the studied vector parameters. Transient episodes were significantly fewer in group D than in group B. In patients with MI, the permanent change of vector parameters evolved more rapidly and reached a plateau earlier in those treated with streptokinase (QRS-VD: 178 +/- 82 vs. 293 +/- 100 min, p < 0.001; ST-VM 20: 142 +/- 75 vs. 293 +/- 89 min, p < 0.005). The magnitude of the end value for QRS-VD correlated with infarct size estimated by the maximal value of creatine kinase (r = 0.89; p < 0.001). We conclude that in patients admitted to the CCU with chest pain, continuous VCG monitoring early differentiates patients suffering from ischemic heart disease (IHD) from patients without IHD. It also differentiates patients with unstable angina from patients with MI.

Patient Characteristics in Cases of Chronic Severe Heart Failure with Different Degrees of Left Ventricular Systolic Dysfunction

It has not been determined previously whether patients with severe chronic congestive heart failure differ in demographic characteristics with respect to left ventricular systolic dysfunction (LVD). In patients with severe chronic congestive heart failure in NYHA IV, an optional protocol in the CONSENSUS-I trial was designed to ascertain whether there were any differences in patient characteristics regarding the degree of LVD defined as left ventricular fractional shortening (FS). A subgroup of 54 patients from the CONSENSUS-I trial were evaluated with M-mode echocardiography. Patients with FS above median (14%) were older (74 +/- 7 vs. 68 +/- 7, p < 0.01), more often female (48 vs. 15%, p < 0.05) and had lower heart rates (77 +/- 15 vs. 95 +/- 17, p < 0.01). Analysis of the 2-year follow-up from the end of the trial was also performed. In the placebo group, patients with FS > 14% had significantly better prognosis than patients with FS < 14%. In the enalapril-treated group no such difference in survival was seen. The difference between the original treatment groups remained, despite the fact that treatment with enalapril was then made available to all surviving patients. In conclusion, patients with advanced chronic congestive heart failure and less severe LVD have different demographic characteristics than patients with more severe LVD. In the placebo group, but not in the enalapril group, prognosis was better in patients with less severe LVD.

Prognosis of patients with stable angina pectoris on antianginal drug therapy

Antianginal drug treatment reduces symptoms and ischemia but may also influence the prognosis of patients with stable angina pectoris. The Atenolol Silent Ischemia Study (ASIST) compared atenolol and placebo treatment (about 140 patient-years on each) in patients with mainly silent ischemia and found less aggravation of angina and a tendency toward fewer cardiac complications with atenolol treatment. The Total Ischaemic Burden European Trial (TIBET) compared slow release nifedipine, atenolol, or the combination (about 450 patient-years on each) and found no significant differences with regard to cardiac complications, a nonsignificant trend toward better prognosis on combined treatment, and more side effects on nifedipine alone compared with the other treatments. The Angina Prognosis Study in Stockholm (APSIS) compared metoprolol and verapamil (about 1,400 patient-years on each) and found similar effects on cardiovascular endpoints, tolerability, and psychosocial variables with the 2 treatments. Hypothesis-generating subgroup analyses in APSIS suggest that treatment effects may differ in hypertensive and diabetic subgroups. Beneficial effects in primary and secondary prevention, together with data from ASIST, suggest that beta 1 blockade influences prognosis favorably. The safety of short-acting nifedipine in ischemic heart disease is questioned, but TIBET data suggest that slow release nifedipine may be safe. Verapamil has beneficial effects after myocardial infarction (Danish Verapamil Infarction Trial II) and shows similar efficacy as metoprolol in the APSIS study. The paucity of placebo data (antianginal treatment cannot be withheld during long periods of time in symptomatic patients) precludes firm conclusions regarding effects of drug treatment on prognosis. It is argued that patients with stable angina pectoris do well on medical treatment, and that beta 1 blockers, verapamil, and, possibly, slow-release nifedipine may influence their prognosis favorably.

Prognostic implications of ambulatory myocardial ischemia and arrhythmias and relations to ischemia on exercise in chronic stable angina pectoris (the Angina Prognosis Study In Stockholm [APSIS])

The prognostic significance of ambulatory ischemia, alone and in relation to ischemia during exercise was assessed in 686 patients (475 men) with chronic stable angina pectoris taking part in the Angina Prognosis Study In Stockholm (APSIS), who had 24-hour ambulatory electrocardiographic registrations and exercise tests at baseline (n = 678) and after 1 month (n = 607) of double-blind treatment with metoprolol or verapamil. Ambulatory electrocardiograms were analyzed for ventricular premature complexes and ST-segment depression. During a median follow-up of 40 months, 29 patients died of cardiovascular (CV) causes, 27 had a nonfatal myocardial infarction, and 89 underwent revascularization. Patients with CV death had more episodes (median 5 vs. 1; p<0.01) and longer median duration (24 vs. 3 minutes; p<0.01) of ST-segment depression than patients without events. For those who had undergone revascularization, the duration was also longer (12 vs. 3 minutes; p<0.05). In a multivariate Cox model including sex, history of previous myocardial infarction, hypertension, and diabetes, the duration of ST-segment depression independently predicted CV death. When exercise testing was included, ambulatory ischemia carried additional prognostic information only among patients with ST-segment depression > or =2 mm during exercise. When the treatment given and treatment effects on ambulatory ischemia were added to the Cox model, no significant impact on prognosis was found. Ventricular premature complexes carried no prognostic information. Thus, in patients with stable angina pectoris, ischemia during ambulatory monitoring showed independent prognostic importance regarding CV death. Ambulatory electrocardiographic monitoring and exercise testing provide complementary information, but only among patients with marked ischemia during exercise. Treatment reduced ambulatory ischemia, but the short-term treatment effects did not significantly influence prognosis.

Prognostic information from on-line vectorcardiography in unstable angina pectoris

The prognostic information from 24-hour monitoring with on-line vectorcardiography (VCG) was assessed in 100 patients with a clinical diagnosis of unstable angina pectoris. ST change vector magnitude, ST vector magnitude and QRS vector difference were monitored. During a follow-up period of 343 +/- 77 days, 7 patients died from cardiac causes and 8 patients had a nonfatal myocardial infarction (MI). Thirty patients were readmitted for unstable angina pectoris and 36 were revascularized because of medical refractory angina. Univariate predictors of cardiac death or nonfatal MI included greater age, rest pain during hospitalization, previous MI, diabetes mellitus and high incidence of supposedly ischemic transient ST and QRS vector changes. In multivariate analysis, a high incidence of transient ST (p < 0.01) and QRS (p < 0.01) vector changes provided additional prognostic information beyond that of clinical and exercise test data. In conclusion, VCG monitoring during the first 24 h of hospitalization for unstable angina pectoris identifies patients with increased risk of adverse cardiac events.

Comparison of Adenosine and Exercise Stress Test for Quantitative Perfusion Imaging in Patients on Beta-Blocker Therapy

Beta-blocker therapy is used to decrease myocardial ischemia during exercise but may cause suboptimal diagnostic performance in exercise stress testing. The aim of the present study was to compare results of quantitative technetium-99-sestamibi single photon emission tomography (SPECT), following exercise stress test or pharmacological stress test with adenosine. We chose adenosine as comparison, since betablockers may not interfere with adenosine induced vasodilatation and therefore possibly may not interfere with its diagnostic performance. Sixteen patients with angiographically documented coronary disease (5 single-vessel, 6 two-vessel and 5 three-vessel disease), who were chronically treated with beta-blockers, performed SPECT imaging at rest, following bicycle exercise and following adenosine infusion in random order. The SPECT data were analyzed visually and quantitatively, using dedicated computer software (CEqual). According to both visual and quantitative SPECT analysis, adenosine was superior to show reversibility. Higher reversibility extent (50 ± 15 vs. 26 ± 12 pixels, p < 0.01) and more intense reversibility severity (110 ± 29 vs. 49 ± 23 sum of SDs, p < 0.05) were observed during adenosine than exercise. Conclusions: Less myocardial perfusion abnormalities during exercise than during adenosine stress in patients treated with beta-blockers may indicate less ischemia but also an impaired diagnostic performance. Thus adenosine stress test should be preferred to optimize the diagnostic sensitivity in patients during beta-blocker treatment.