Mobilization of CD34/CXCR4+, CD34/CD117+, c-met+ stem cells, and mononuclear cells expressing early cardiac, muscle, and endothelial markers into peripheral blood in patients with acute myocardial infarction

BACKGROUND

Adult stem cells can contribute to myocardial regeneration after ischemic injury. Bone marrow and skeletal muscles contain a population of CXCR4+ cells expressing genes specific for muscle progenitor cells that can be mobilized into the peripheral blood. The aims of the study were (1) to confirm the presence of early tissue-committed cells expressing cardiac, muscle, and endothelial markers in populations of mononuclear cells in peripheral blood and (2) to assess the dynamics and magnitude of the mobilization of CD34+, CD117+, CXCR4+, c-met+, CD34/CD117+, and CD34/CXCR4+ stem cells into peripheral blood in relation to inflammatory and hematopoietic cytokines in patients with ST-segment-elevation acute myocardial infarction (STEMI).

METHODS AND RESULTS

Fifty-six patients with STEMI (<12 hours), 39 with stable angina, and 20 healthy control subjects were enrolled. Real-time reverse transcription-polymerase chain reaction (RT-PCR) was used for detection of tissue-specific markers. The number of the cells was assessed by use of a flow cytometer on admission, after 24 hours, and after 7 days. RT-PCR revealed increased expression of mRNA (up to 3.5-fold increase) for specific cardiac (GATA4, MEF2C, Nkx2.5/Csx), muscle (Myf5, Myogenin, MyoD), and endothelial (VE-cadherin, von Willebrand factor) markers in peripheral blood mononuclear cells. The number of CD34/CXCR4+ and CD34/CD117+ and c-met+ stem cells in peripheral blood was significantly higher in STEMI patients than in stable angina and healthy subjects, peaking on admission, without further significant increase after 24 hours and 7 days.

CONCLUSIONS

The study demonstrates in the setting of STEMI a marked mobilization of mononuclear cells expressing specific cardiac, muscle, and endothelial markers as well as CD34/CXCR4+ and CD34/CD117+ and c-met+ stem cells and shows that stromal cell-derived factor-1 is an important factor influencing the mobilization.

Increased variability of the coupling interval of premature ventricular beats may help to identify high-risk patients with coronary artery disease

OBJECTIVE

The purpose of this study was to determine the characteristics and predictive value of the variability of coupling interval of ventricular premature beats (VPBs) for cardiac mortality in patients with coronary artery disease (CAD).

BACKGROUND

Frequent VPBs have been linked to an increased risk for cardiac death in patients with coronary artery disease. It is unknown whether analysis of coupling interval of VPBs from ambulatory ECG recordings can be used for risk statification in these patients.

METHODS

In 78 consecutive symptomatic patients with documented CAD who presented with frequent VPBs (>720/24 h), the analysis of VPBs' coupling interval (SDNV) was performed. Left ventricular function, ventricular arrhythmias and simple measures of heart rate variability were assessed. Mean follow-up was 702+/-329 days. Cardiac mortality was the primary end-point of the study.

RESULTS

During follow-up, 14 patients died-11 deaths were cardiac. Left ventricular ejection fraction (LVEF)<40%; no beta-blocker treatment and digoxin use were clinical variables showing a significant association with cardiac mortality. The presence of non-sustained ventricular tachycardia (nsVT), especially if more than five episodes were present; short mean sinus cycle (<750 ms) and SDNV were associated with cardiac deaths. Mean SDNV was 79+/-29 in victims and 63+/-29 in survivors (p<0.05). Univariate Cox regression analysis revealed that the presence of SDNV>80 ms carried a relative risk of 6.7 for cardiac mortality. The adjusted relative risk was 13.3 for nsVT and 4.4 for SDNV>80 ms. Among patients with nsVT, mortality rate was significantly higher with SDNV>80 ms (58%), compared to lower SDNV (14%, p<0.01). Sixty-four percent mortality rate was observed in patients with LVEF<40%, presence of nsVT and SDNV>80 ms, compared to 17% in similar patients with lower SDNV (p<0.05).

CONCLUSION

The analysis of coupling interval of ventricular premature beats form the same 24-h ECG recordings may complement the standard Holter analysis for risk stratification. This seems especially promising in the subgroups of patients at highest risk-those with LV systolic dysfunction, non-sustained VT or both.

[Transthoracic Doppler echocardiography for the non-invasive assessment of coronary flow reserve--a case report]

We describe a case of a 55-year-old male with anterior myocardial infarction, treated in the acute phase with thrombolysis. Transthoracic echocardiography showed hypokinetic apical segments, ejection fraction of 55% and reduced coronary flow reserve in the left anterior descending (LAD) coronary artery. Elective coronary angiography revealed a borderline (40-50%) lesion in LAD. The patient underwent successful angioplasty of LAD with stent implantation. Non-invasive coronary flow reserve measurements were repeated 3 days, 6 weeks and 6 months after angioplasty showing continuous improvement in this parameter. The role of non-invasive echocardiographic assessment of coronary flow reserve in the selection for angioplasty and monitoring of the effects of treatment is discussed.

[Prevalence of risk factors for atherosclerosis in participants of the Southern Poland Epidemiological Survey (SPES) with normal blood pressure]

Results of many studies indicate that cardiovascular diseases develop more often in subjects with blood pressure higher than optimal, but lower than the level, at which the diagnosis of arterial hypertension and implementation of therapy is justifiable. The aims of this study were the assessment of prevalence of risk factors for atherosclerosis among people with normal blood pressure in a population of Southern Poland (Southern Poland Epidemiological Survey--SPES), the quantitative evaluation of global risk for coronary events in relation to normal blood pressure classes, as well as the estimation of the size of subpopulation of subjects eligible for lipid-lowering treatment. A subpopulation of 15,484 subjects without known hypertension and coronary heart disease with normal blood pressure measurements were chosen from a total of 50,111 participants of the SPES study. There were 5,304 men and 10,180 women, aged from 18 to 87 years. Optimal blood pressure (< 120/80) was observed in 24%, normal (120-129/80-84) in 40% and high normal (130-139/85-89) in 35% subjects. In both sexes, irrespective of blood pressure classes, the most prevalent risk factors were hypercholesterolemia, overweight/obesity and smoking. The prevalence of hypercholesterolemia (> 200 mg/dl) increased along with blood pressure classes, and the proportion of subjects with cholesterol level > or = 240 was 1.5 times greater in those with high normal (21%), compared to those with optimal blood pressure (13%). The proportion of overweight/obesity was 1.5 times greater in subjects with high normal (50.5%) when compared to those with the optimal blood pressure (32.5%). The global risk for coronary events > 10% was more frequent in subjects with high normal blood pressure. Increase of the proportion of subjects eligible for lipid-lowering therapy from near 0% in women with optimal to approximately 10% in men and 8% in women with high normal blood pressure. A rise of the normal blood pressure class is associated with a clear increase in the prevalence of atherosclerotic risk factors and the global coronary risk. An extended medical care should be considered to all subjects with high normal blood pressure and global risk greater than 10%, including lipid-lowering therapy in approximately 10% of this subpopulation.

Cytomegalovirus infection in acute myocardial infarction. Is there a causative relationship?

BACKGROUND

Cytomegalovirus (CMV) infection has been suggested to play an important role in the pathogenesis of atherosclerosis. Whether CMV may be involved in the development of acute myocardial infarction (MI) has not yet been established.

AIM

To asses the prevalence of active or latent CMV infection in patients with angina or acute MI.

METHODS

The study group consisted of 158 subjects divided into three groups: group I - 70 patients (49 males, mean age 57.1+/-10.4 years) with acute MI, group II - 40 patients (21 males, mean age 59.1+/-7.9 years) with stable angina, and group III - 48 healthy controls (18 males, mean age 54.9+/-12.1 years). Anti-CMV IgM and IgG antibody titre in blood serum was measured in all subjects. In those in whom anti-CMV antibodies were present, quantitative polimerase chain reaction (Q-PCR) was performed in order to detect DNA of CMV in peripheral blood mono-nuclear cells (PBMC) and in serum.

RESULTS

Anti-CMV IgM antibodies were not detected in any of the subjects. A positive result of anti-CMV IgG test was present in 60 (85.7%) patients from group I, 34 (85%) patients from group II, and 15 (31.5%) control subjects. The mean IgG antibody concentration was 72.2+/-13.6 aU/ml, 74.23+/-12.8 aU/ml and 19.57+/-3.56 aU/ml, respectively (p<0.001). In patients from group I, a significantly higher prevalence of serum DNA CMV was noted than in the remaining groups.

CONCLUSIONS

Patients with symptomatic coronary artery disease have a significantly higher anti-CMV antibody titre than healthy subjects. The active form of infection is significantly more prevalent in patients with acute MI than in patients with stable angina.

Three novel mutations in exon 21 encoding beta-cardiac myosin heavy chain

Familial hypertrophic cardiomyopathy has a complex multigenic background. Previous work allowed to determine one of the gene loci responsible for this disease on chromosome 14 band q11-q12, and linked it to the alpha and beta-cardiac myosin heavy chains. In this study we demonstrate changes in exon 21, coding for beta-myosin heavy chain. We described 4 patients from different families with an unequivocal diagnosis of hypertrophic cardiomyopathy based on the clinical picture. Direct sequencing of exon 21 revealed the presence of 5 novel mutations. Two of the mutations in codons 771 and 781 revealed in our study did not result in any changes in amino acid sequence. The next three were as follows: in codon 782 (AGC > GAC) transition responsible for Ser-->Asp substitution; in codon 779 (GAG > TAG) mutation that results in replacement of Glu-->Stop; in codon 774 (GAG > GTG) which is expressed as substitution of Glu-->Val. These mutations are located close to mutations identified and described in the literature, so they are likely to cause similar symptoms.

Collaborative Angiographic Patency Trial Of Recombinant Staphylokinase (CAPTORS II)

AIMS

A fibrinolytic agent more effective than streptokinase available for bolus injection with reasonable cost-effectiveness is a desirable goal. Pilot studies with bolus pegulated staphylokinase (PEG-Sak) have revealed excellent Thrombolysis In Myocardial Infarction (TIMI) 3 60-minute flow.

METHODS AND RESULTS

We evaluated patients with acute ST-elevation myocardial infarction within 6 hours of chest pain onset to determine a dose of PEG-Sak that had at least equal efficacy to recombinant tissue plasminogen activator (rt-PA) while maintaining an acceptable safety profile. After the initial study of 38 patients, of whom 27 received PEG-Sak, enrollment was temporarily halted because 3 patients receiving PEG-Sak had intracranial hemorrhage: 1 at a dose of 0.15 mg/kg and 2 at a dose of 0.05 mg/kg. Overall, 378 patients were studied across a PEG-Sak dose range from 0.01 mg/kg to 0.015 mg/kg, and 122 patients received accelerated rt-PA. At the lowest dose of PEG-Sak studied, 0.01 mg/kg, there was suggestive evidence of attenuation of efficacy; the point estimate for TIMI 3 flow was 24% (95% CI 9%-38%). At doses of 0.01875 to 0.0375 mg/kg (n = 314), TIMI 3 flow rates were 33% (95% CI 27%-38%), whereas the TIMI 3 flow was 41% (95% CI 20%-61%) at the highest PEG-Sak dose studied, 0.05 mg/kg (n = 23), which was similar to that found with rt-PA, 41% (95% CI 32%-50%).

CONCLUSION

The efficacy of PEG-Sak, coupled with its ease of administration, provide further impetus for further study in acute myocardial infarction.

[Primary coronary angioplasty with the use of embolic protection device - a case report]

A case of 65 year old male with acute myocardial infarction is described. The patient underwent successful primary coronary angioplasty with the use of a distal embolic protection device.

Left ventricular systolic function in myocardial infarction survivors treated with primary angioplasty, thrombolysis of angioplasty preceded by thrombolysis

BACKGROUND

Acute myocardial infarction (AMI) may be treated with thrombolysis, primary angioplasty or a combination of both methods. Preservation of left ventricular systolic function is an important goal of treatment.

AIM

To assess whether the mode of treatment of AMI influences left ventricular systolic function measured 6 months after AMI.

METHODS

In a group of 108 patients who survived AMI, an echocardiographic examination was performed 6 months afterwards. Ejection fraction, wall motion score index, asynergy area index, infarcted wall motion score index and apical segments motion score index were measured. Patients were divided into three groups: those treated with thrombolysis only, treated with angioplasty or those who underwent angioplasty preceded by thrombolysis.

RESULTS

Global left ventricular systolic function was similar in all three groups. Compared to the two remaining groups, the group treated with combined therapy had significantly worse indexes of infarcted wall motion score and apical segments motion score. This group also included a significantly higher number of patients with akinetic or dyskinetic apical segments.

CONCLUSIONS

Echocardiographic examination of global left ventricular systolic function in MI survivors performed 6 months after AMI, reveals similar values regardless of the method used for AMI treatment. However, segmental systolic function in the area of infarcted wall and apical segments is significantly more altered in patients treated with angioplasty preceded by thrombolysis than in other analysed patients.

Plasma endothelin-1 in patients with stable or unstable angina

BACKGROUND

It has been documented that an elevated endothelin-1 (ET-1) plasma concentration is associated with an increased risk of serious coronary events and the presence of angiographically documented coronary artery disease (CAD). The results of a few studies which examined ET-1 plasma level in patients with stable or unstable angina, were inconclusive.

AIM

To assess whether ET-1 blood concentration measured in the coronary sinus and peripheral vein is associated with clinical symptoms in patients with multi-vessel CAD.

METHODS

The study group consisted of 23 patients with multi-vessel CAD of whom 11 had unstable angina and 12 - stable angina. Both groups were matched with regard to age, gender and the presence of cardio-vascular risk factors. Blood samples for ET-1 assessment were taken during coronary angiography simultaneously from the coronary sinus and femoral vein. ET-1 was measured using an immunoenzymatic method.

RESULTS

ET-1 plasma level in the peripheral venous circulation was similar in patients with unstable or stable angina (0.45+/-0.18 pmol/L versus 0.46+/-0.14 pmol/L, NS) whereas ET-1 level in the coronary sinus was significantly higher in patients with unstable angina (1.44+/-0.47 pmol/L versus 0.34+/-0.17 pmol/L, p<0.05).

CONCLUSIONS

ET-1 concentration in the coronary sinus is significantly higher in patients with unstable rather than stable angina which confirms the role of ET-1 in the pathogenesis of CAD. Our results suggest a possible future role of endothelin receptor blockers in the treatment of patients with unstable angina.

[Results of treating myocardial infarction patients with ST segment elevation in Górnoślaskim Ośrodku Kardiologii in Katowice]

BACKGROUND

Reperfusion therapy reduces mortality rate in patients with acute myocardial infarction with ST-segment elevation (STEMI).

AIM

The aim of the study was to access the early outcome of patiens (pts) with STEMI admitted to Upper Silesian Cardiology Centre in 2002.

METHODS

957 pts with AMI were enrolled into the study. The influence of several factors on in-hospital mortality was analised.

RESULTS

Out of 957 pts 51 died during hospitalization (5,3%). Coronary angiography was performed in 98,0% of pts. Primary PTCA was performed in 94,5% of pts. Stents were implanted in 85,9% of patients who underwent PTCA. The following factors significantly contributed to increased mortality among pts with acute myocardial infarction: female sex (p<0,02), multivessel disease (p<0,05), age above 65 yrs (p<0,001), time from the onset of chest pain above 6 hours (p<0,01) and 12 hours (p<0,001). The use of GP IIB/IIIA inhibitors significantly reduced the mortality rate (p<0,05). Cardiogenic shock was the only independent factor of the increased risk of mortality in multivariate regression analysis (p<0,0001) with relative risk of death (RR 33,5). The mortality rate in pts with shock was 40,2%: 70,8% in case of conservative treatment, 70% in the group of failed PTCA and only 17,2% in the group of successful PTCA. Among pts who underwent primary PTCA the failure to restore coronary blood flow of the infarct related artery contributed to increased relative risk of death (RR 14,5) (p<0,001). Stents improved the survival rate (p<0,01). In PTCA group cardiogenic shock and failed PTCA were independent risk factors in multivariate regression analysis.

CONCLUSIONS

The results of our study show low rate of in-hospital mortality in pts without cardiogenic shock (1,2%). PTCA is highly successful method of treatment of pts with shock with mortality rate 17,2% in pts who underwent successful procedure.

[Assessment of interventions conducted in the program Southern Poland Epidemiological Survey in adults with high hypercholesterolemia]

In 1997 the Southern Poland Epidemiological Survey trial was conducted, the largest primary prevention action in Poland, which comprised 50,111 subjects. In this trial subjects with total cholesterol over 300 mg% were identified. After two years period these subjects were contacted to assess the kind and effectiveness of their action to reduce hypercholesterolemia and other CAD risk factors. The role of general practitioner was also addressed. The aim of the present study was to assess the influence of primary prevention on the following parameters: intensity and frequency of risk factors occurrence, rate of individual risk of coronary heart disease in the study group and the assessment of influence of primary care physician action on risk factors reduction in the study population. 1090 persons were invited into the study. 293 (27%) of them came to the hospital for further investigation. After exclusion of patients in whom CAD was already present in 1997, a group of 263 patients was analyzed. The study group was divided in three parts: non-compliant to the primary prophylaxis recommend alians (52 pers.), performing the primary prophylaxis recommendations on their own (113 pers.), and performing the recommendations under supervision of the general practitioner (89 pers.). Blood pressure, smoking, weight reduction, physical activity improvement and lowering of the total cholesterol were analyzed. The risk of CAD in 1997 in 1999 was evaluated according to the risk score. In the group following the recommendations unders medical supervision significant CAD risk reduction, lowest CAD risk in 1999, highest ratio of smoking quitting, tendency to physical activity improvement, highest weight reduction (especially in people with visceral obesity), and the lowering of total cholesterol level were observed. In the group following the recommendations without medical supervision significant level of smoking quitting and weight reduction were observed. In this group total cholesterol level and CAD risk were unchanged. On the basis of these results following conclusions were formed: 1) Prevention action caused smoking quitting, body mass reduction, total cholesterol reduction and tendency to improved physical activity. 2) Prevention action caused only minor personal CAD risk reduction. 3) General practitioner activity lowered CAD incidence risk. 4) Education of people at risk, general practitioners and the entire population on avoiding coronary artery disease is necessary.

[Heart rate variability in patients with hypertrophic cardiomyopathy and in their close relatives]

The results of HRV analysis in patients with hypertrophic cardiomyopathy (HCM) are conflicting. We evaluated short-term HRV in patients with familiar HRV and in their close relatives. 31 families of patients with HCM were examined. There were 43 patients with HCM confirmed by 2D-echo (HCM-group, 23 f, 20 m, aged 46 +/- 14 ys), and 157 family members (REL-group, 75 f, 82 m, aged 29 +/- 17 ys). The control group consisted of 180 healthy subjects (80 f, 100 m, aged 33 +/- 12 ys). In each subject 512 consecutive sinus beats were recorded in supine position during spontaneous breathing using computer-assisted amplifier (A/D 12 bit, 1 kHz). Mean RR interval (RRI, ms), its standard deviation (SDRR, ms) and spectral measures (FFT, Blackman-Harris window): PSD of high frequency (HF) and low frequency (LF) [ms2/Hz], as well as respiratory rate (BPM) were measured. Patients with HCM had significantly shorter RRI (867 +/- 121) as compared to the controls (919 +/- 138, p < 0.05). The RRI was also shorter in the relatives (851 +/- 150, p < 0.01). In HCM and REL groups the respiratory rate was faster (16.7 +/- 3.0 and 17.1 +/- 3.4, respectively), as compared to the controls (14.5 +/- 2.9, both p < 0.01). The HRV measures were reduced in the HCM-group (SDRR 31.4 +/- 10.6, lnHF 7.71 +/- 0.65, lnLF 8.22 +/- 0.65 and LF/HF 1.07 +/- 0.10), as compared to the controls (SDRR 64.8 +/- 23.9, lnHF 8.79 +/- 0.61, lnLF 8.87 +/- 0.65, all p < 0.001 and LF/HF 1.01 +/- 0.07, p < 0.01). In the REL-group SDRR and lnHF were significantly reduced (SDRR 52.4 +/- 24.1, lnHF 8.48 +/- 0.78, p < 0.001), while the remaining parameters were comparable. The HRV reduction was more expressed in HCM-patients and family-members < 30 years of age. A significantly reduced age-, sex- and RRI-adjusted SDNN was observed in 54% pts in HCM-group and in 42% subjects in members-group. Reduced heart rate variability is frequently seen not only in patients with diagnosed HCM, but also in a substantial number of their kindred.

Selectin-P and interleukin-8 plasma levels in coronary heart disease patients

BACKGROUND

Alterations of the immune system are now believed to play crucial role in the pathogenesis of atherosclerosis. The aim of this study was analysis of soluble forms of selectin-P and interleukin-8 levels in patients with different form of coronary heart disease.

MATERIALS AND METHODS

In the study took part 18 patients with stable coronary heart disease, 20 patients with unstable coronary heart disease and 15 healthy persons from control group. Soluble selectin-P and interleukin-8 levels were measured in EDTA plasma with the use of enzyme immunoassay ELISA.

RESULTS

The level of soluble selectin-P was significantly higher in unstable coronary heart disease patients in comparison to the stable coronary heart disease patients (P < or = 0.01) and nonsignificantly higher in comparison to the control group. The level of interleukin-8 were significantly higher in unstable coronary heart disease patients in comparison to the stable coronary heart disease patients (P < or = 0.01) and in comparison to the control group (P < or = 0.02).

CONCLUSION

Our findings suggest that soluble form of selectin-P and interleukin-8 may be useful clinical predictors of unstable coronary heart disease. The assessment of the risk for the development of coronary heart disease requires further serial investigation.

[Prevalence of main risk factors for ischemic heart disease in a cohort of 41,972 participants from Southern Poland Epidemiological Survey]

Southern Poland Epidemiological Survey (SPES) was carried out in 1997 in the former Katowice and Bielsko voivodeships with the aim of cardiovascular disease prevention. One of the objectives of SPES was to establish the prevalence of the risk factors for atherosclerosis. This paper describes a group of 41,927 adults (24,985 women and 16,942 men) with no signs and symptoms of ischaemic heart disease who participated in the study, comprising 83.7% of all the examined cohort. Hypercholesterolemia and hypertension, present in 55.8% and 45.3% of subjects respectively, were found to be the main risk factors in both men and women. Hypercholesterolemia was more prevalent in older age groups. 33.7% of women and 46.3% of men were overweight, 23.9% and 17% respectively were obese. 22.4% of women and 31.9% of men were active smokers. Smoking was more common in younger age groups. 25.3% of women and 21.5% of men had a positive family history for ischaemic heart disease before the age of 60 years. High prevalence of classical risk factors in the examined group indicates that population strategy should be introduced in primary prevention of cardiovascular disease in this area.

[Subjective quality of life in patients with coronary artery disease after percutaneous coronary angioplasty in elderly patients after 65 years of age]

The aim of our study was to determine the quality of life in elderly patients after PTCA using the SF 36 questionnaire measuring post procedural physical and mental health.

STUDY GROUP

71 pts > 65 years (M-46, F-25), mean age 70.92 +/- 3.49, post PTCA were examined with SF 36 questionnaire.

CONTROL GROUP

73 pts < 65 years (M-61, F-12) mean age 53.6 +/- 7.37, post PTCA. The mean follow-up time was 19.3 +/- 3.2 month in the study group and 18.8 +/- 8.5 month in the control group (NS). The mean physical component summary score was 67.2 vs 69.7 points (NS) in the control group. The mean mental component summary score was 72.3 vs 74.4 points (NS) respectively. There were no significant differences between the groups in the following multi item domains: general health, vitality, social functioning, emotional role functioning and mental health, except physical functioning: 73.5 vs 76.3 points, p < 0.008 respectively. Additional questions asked revealed high satisfaction with performed PTCA, similar in both groups: 65 pts (91.6%) vs 71 pts (98.6%) (NS). 70 (99%) elderly pts considered this method most valuable and would undergo this procedure eagerly again, if necessary. During the observation 21 (29.6%) elderly pts required hospitalization because of the chest pain, 2 pts (2.8%) had nonfatal myocardial infarction and 3 pts (4.2%) underwent surgical revascularisation (CABG). In the control group 12 pts (16.4%) were re-hospitalized, 1 pt (1.4%) required CABG and no acute cardiac events were observed. Smoking was continued significantly more frequently in the younger pts: 12 (16.4%) vs 2 (2.8%) p = 0.05. 72 (98.6%) younger pts and 60 (84.5%) elderly pts reported regular cholesterol level control (NS). Our data suggest that PTCA in elderly pts with symptomatic coronary artery disease, is well tolerated and reflects positively in their quality of life after the procedure.

Efficacy and safety of dofetilide in the prevention of symptomatic episodes of paroxysmal supraventricular tachycardia: a 6-month double-blind comparison with propafenone and placebo

BACKGROUND

Existing drug therapies for paroxysmal supraventricular tachycardia (PSVT) have potentially serious adverse effects. Dofetilide, a pure class III antiarrhythmic agent, may offer an effective and safe alternative for treating PSVT. This study compared the efficacy and safety of dofetilide with that of propafenone and placebo in the prevention of PSVT.

METHODS

This multicenter, randomized, placebo-controlled, parallel-group study compared the effectiveness of oral dofetilide 500 microg given twice daily with that of propafenone 150 mg given 3 times a day and placebo in preventing the recurrence of PSVT in 122 symptomatic patients. Episodes of PSVT were documented by symptom diaries and Hertcard (Hertford Medical, Hertfordshire, UK) event recorders.

RESULTS

After 6 months of treatment, patients taking dofetilide, propafenone, and placebo had a 50%, 54%, and 6% probability, respectively, of remaining free of episodes of PSVT (P <.001 for both dofetilide and propafenone vs placebo). Both dofetilide and propafenone also decreased the frequency of episodes of PSVT; the median numbers of episodes in the dofetilide- and propafenone-treated groups were 1 and 0.5, respectively, compared with 5 in the placebo-treated group. Dofetilide was well tolerated; no proarrhythmia occurred. Three patients taking propafenone had serious treatment-related adverse effects that required drug discontinuation.

CONCLUSIONS

Dofetilide and propafenone were equally effective in preventing the recurrence of or decreasing the frequency of PSVT.

Mutation A1298C of methylenetetrahydrofolate reductase: risk for early coronary disease not associated with hyperhomocysteinemia

Diminished activity of 5,10 methylenetetrahydrofolate reductase (MTHFR), a regulatory enzyme of homocysteine metabolism, may predispose to coronary artery disease (CAD). In a case-control study we determined the prevalence of two common MTHFR polymorphisms, C677T and A1298C, in 161 male patients under the age of 50 years with angiographically documented CAD and compared it to that in 211 healthy controls. Genotyping was also performed in a random population sample, consisting of 149 men and 121 women at an average age of 40 years. The studied group had classic risk factors of atherosclerosis but did not differ in fasting plasma homocysteine, folic acid, and vitamin B12 levels in either the control group or population sample. The frequency of the 1298C allele was significantly higher in CAD (0.304) than in controls (0.199) or the population sample (0.235). Allele 1298C showed a significant association with early-onset CAD both in homozygotes and in heterozygous carriers. These findings were further supported by comparisons with the population sample. Homozygosity for allele 677T showed a tendency to associate with CAD. Allele 1298C of MTHFR is associated with early-onset CAD (carriers- RR = 1.71, 95% CI: 1.13-2.59; homozygotes- RR = 3.09, 95% CI: 1.36-7.02), even when blood homocysteine levels are not elevated.

Effect of carvedilol on survival in severe chronic heart failure

BACKGROUND

Beta-blocking agents reduce the risk of hospitalization and death in patients with mild-to-moderate heart failure, but little is known about their effects in severe heart failure.

METHODS

We evaluated 2289 patients who had symptoms of heart failure at rest or on minimal exertion, who were clinically euvolemic, and who had an ejection fraction of less than 25 percent. In a double-blind fashion, we randomly assigned 1133 patients to placebo and 1156 patients to treatment with carvedilol for a mean period of 10.4 months, during which standard therapy for heart failure was continued. Patients who required intensive care, had marked fluid retention, or were receiving intravenous vasodilators or positive inotropic drugs were excluded.

RESULTS

There were 190 deaths in the placebo group and 130 deaths in the carvedilol group. This difference reflected a 35 percent decrease in the risk of death with carvedilol (95 percent confidence interval, 19 to 48 percent; P=0.00013, unadjusted; P=0.0014, adjusted for interim analyses). A total of 507 patients died or were hospitalized in the placebo group, as compared with 425 in the carvedilol group. This difference reflected a 24 percent decrease in the combined risk of death or hospitalization with carvedilol (95 percent confidence interval, 13 to 33 percent; P<0.001). The favorable effects on both end points were seen consistently in all the subgroups we examined, including patients with a history of recent or recurrent cardiac decompensation. Fewer patients in the carvedilol group than in the placebo group withdrew because of adverse effects or for other reasons (P=0.02).

CONCLUSIONS

The previously reported benefits of carvedilol with regard to morbidity and mortality in patients with mild-to-moderate heart failure were also apparent in the patients with severe heart failure who were evaluated in this trial.

Overview of the results of recent beta blocker trials

Results of the studies published or reported within the last 2 years provide convincing evidence that beta-blockers can decrease mortality in patients with chronic symptomatic heart failure because of left ventricular systolic dysfunction. The Cardiac Insufficiency Bisoprolol Study (CIBIS)-II and Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure (MERIT-HF) trials showed a 34% reduction in all-cause death with bisoprolol and metoprolol therapy in patients with class II-III heart failure. Data from Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS), with a 35% mortality reduction, extended this benefit to class IV patients treated with carvedilol who do not require intravenous diuretics or positive inotropes. Ongoing beta-blocker studies address new topics, such as treatment of older patients, in whom diastolic heart failure may be more common, and direct comparison of different drugs. Although the use of beta-blockers for heart failure tends to increase, implementation of the knowledge from the trials in clinical practice still remains a challenge.

[Long-term observation of exercise capacity and left ventricular function in patients with coronary heart disease treated surgically and conservatively]

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Local delivery of enoxaparin to decrease restenosis after stenting: results of initial multicenter trial: Polish-American Local Lovenox NIR Assessment study (The POLONIA study)

BACKGROUND

Enoxaparin inhibits smooth muscle cell proliferation in experimental models. Intimal hyperplasia has been found to be the principal cause of restenosis after coronary stent implantation. We sought to determine whether the intramural delivery of enoxaparin before stenting of de novo lesions decreases restenosis.

METHODS AND RESULTS

One hundred patients who were undergoing stenting were randomly assigned to either local administration of enoxaparin during predilation with reduced systemic heparinization or stenting with standard, systemic heparinization. All patients were treated with the same type of stent (NIR). The primary study end point was late luminal loss. The secondary end points were major adverse cardiac events, target lesion revascularization, and angiographic restenosis at 6 months. Angiographic follow-up at 6 months was completed in all except 1 patient. Late luminal loss was reduced to 0.76+/-0.42 mm in the local enoxaparin delivery group versus 1. 07+/-0.49 mm in the systemic heparinization group (P:<0.001). Restenosis, using a binary definition, occurred in 10% of patients in the enoxaparin group and in 24% of patients in the systemic heparinization group (P:<0.05). Target lesion revascularization rates occurred in 8% of the enoxaparin group and 22% of the systemic heparinization group (P:<0.05). There were no deaths and no emergent CABGs were performed. The only subacute stent closure and non-Q-wave infarction occurred in a patient assigned to the systemic heparinization group.

CONCLUSIONS

This is the first prospective randomized trial in which the local delivery of a drug, enoxaparin, resulted in significant reduction in late luminal loss and restenosis after stent implantation in de novo coronary lesions.