Infarct size and recurrence of ventricular arrhythmias after defibrillator implantation

Infarct size as determined by perfusion imaging is an independent predictor of mortality after implantable cardioverter defibrillator (ICD) implantation in patients with coronary artery disease (CAD) and life-threatening ventricular arrhythmias (VA). However, its value as a predictor of VA recurrence and hospitalisation after ICD implantation is unknown. Therefore, the objective of this study was to evaluate whether infarct size as determined by perfusion imaging can help to identify patients who are at high risk for recurrence of VA and hospitalisation after ICD implantation. We studied 56 patients with CAD and life-threatening VA. Before ICD implantation, all patients underwent a uniform study protocol including a thallium-201 stress-redistribution perfusion study. A defect score as a measurement of infarct size was calculated using a 17-segment 5-point scoring system. Study endpoints during follow-up were documented episodes of appropriate anti-tachycardia pacing and/or shocks for VA and cardiac hospitalisation for electrical storm (defined as three or more appropriate ICD interventions within 24 h), heart failure or angina. After a mean follow-up of 470+/-308 days, 22 patients (39%) had recurrences of VA. In univariate analysis, predictors for recurrence were: (a) ventricular tachycardia (VT) as the initial presenting arrhythmia (86% vs 59% for patients without ICD therapy, P=0.04), (b) treatment with beta-blockers (36% vs 68%, P=0.03) and (c) a defect score (DS) > or = 20 (64% vs 32%, P=0.03). In multivariate analysis, VT as the presenting arrhythmia (chi2=5.51, P=0.02) and a DS > or = 20 (chi2=4.22, P=0.04) remained independent predictors. Cardiac hospitalisation was more frequent in patients with a DS > or = 20 (44% vs 13% for patients with DS < 20, P=0.015) and this was particularly due to more frequent hospitalisations for electrical storm (24% vs 3% for patients with DS < 20, P=0.037). The extent of scarring determined by perfusion imaging can separate patients with CAD into high- and low-risk groups for recurrence of VA and cardiac hospitalisation after ICD implantation.

Haptoglobin 1F allele frequency is high among indigenous populations in the state of Durango, Mexico

We studied haptoglobin polymorphism in Mexican populations with high Indian ancestry living in isolated and urban areas in the state of Durango. Analysis with respect to the HP*1F and HP*1S allelic subtypes by isoelectric focusing showed unusually high HP*1F allele frequencies among urban (0.370) and isolated Mexican Indians (0.383). Comparison with other population studies demonstrated a geographical cline of the HP*1F allele increasing in the same direction of the HP*1 allele, while HP*1S frequency does not show racial differences.

Aldosterone and vascular damage

Although the aldosterone escape mechanism is well known, aldosterone has often been neglected in the pathophysiologic consequences of the activated renin-angiotensin-aldosterone system in arterial hypertension and chronic heart failure. There is now evidence for vascular synthesis of aldosterone aside from its secretion by the adrenal cortex. Moreover, aldosterone is involved in vascular smooth muscle cell hypertrophy and hyperplasia, as well as in vascular matrix impairment and endothelial dysfunction. The mechanisms of action of aldosterone may be either delayed (genomic) or rapid (nongenomic). Deleterious effects of aldosterone leading to vascular target-organ damage include (besides salt and water retention) decreased arterial and venous compliance, increased peripheral vascular resistance, and impaired autonomic vascular control due to baroreflex dysfunction.

A non-invasive cardiovascular index for the quantification of arterial load

OBJECTIVE

Our aim is to quantify steady and pulsatile components of arterial load in a concise and sensitive way by means of a new non-invasive cardiovascular index (NICI).

METHODS AND RESULTS

NICI is based on non-invasively measured pressure (sphygmomanometer), stroke volume index and cardiac index (Doppler echocardiography and ECG) and yields a numerical value (in mm Hg). It expresses the difference between the actual arterial load and reference loading conditions as determined in a control group (29 M/35 F, age 34 +/- 13 yr.) of healthy subjects, with blood pressure 116/61 mm Hg (systolic/diastolic), stroke volume index (SVI) 34 +/- 18 ml.m-2 and cardiac index (CI) 2.1 +/- 0.5 l.min-1.m-2. NICI was calculated in the control group and in 23 borderline hypertensive subjects (10 M/13 F, age 65 +/- 12 yr.) with blood pressure 156/79 mm Hg, SVI 36 +/- 10 ml.m-2 and CI 2.4 +/- 0.6 l.min-1.m-2. NICI was higher in borderline hypertensives (33 +/- 51 vs. 0 +/- 34 mm Hg; P < 0.001) and was strongly correlated with total peripheral resistance index (r = 0.89; P < 0.001) and with the ratio of SVI and pulse pressure (r = -0.89; P < 0.001), expressing the combined effect of both known determinants of cardiac load. NICI was also correlated with effective arterial elastance index (r = 0.89; P < 0.001).

CONCLUSIONS

NICI quantifies, within a logical biomechanical framework, the arterial load as seen by the ejecting ventricle. It combines steady and pulsatile components of arterial load and has a single control value of zero mm Hg.

Continuous monitoring of haemodynamic parameters in humans during the early phase of simulated diving with and without breathholding

This study examined the integrative changes of blood pressure (BP) and stroke volume (SV) leading to the initial biphasic heart rate (fc) response (first 15 s) in simulated diving manoeuvres with and without breathholding (BH). Simulated diving was studied in ten young healthy volunteers by application of a gel-filled pack at 0 degree C and 18 degrees C on the forehead with and without BH. Beat-by-beat and second-to-second fc, BP, SV, and total peripheral vascular resistance (TPR) were followed by continuous non-invasive monitoring. In all conditions (BH with forehead cooling at 0 degree and 18 degrees C) there was an early rise in BP triggering the first tachycardial response (fc acceleration) which was immediately counteracted by the concurrent further increase of SV leading to the second phase of early bradycardic response (fc deceleration). Furthermore, the continuous beat-by-beat and second-to-second monitoring allowed the documentation of a highly significant increase of TPR within the first few seconds of the manoeuvres. Our data further indicated that the differences in haemodynamics observed during the stimuli at different temperatures was overruled by BH. Detailed comparisons of the beat-by-beat and second-to-second analyses were unable to show that one method was better than the other. Using continuous non-invasive monitoring of haemodynamic variables during simulated diving manoeuvres it was possible to provide better insights into the physiological principles and meaning of the diving reflex in humans.

Long-term effects of clinical outcome with low and high dose in the Captopril in Heart Insufficient Patients Study (CHIPS)

BACKGROUND

Although angiotensin-converting enzyme inhibitors are recommended as first line therapy in patients with chronic heart failure, the target doses proven to be effective in major morbidity and mortality trials (e.g. captopril 50 mg b.i.d), are generally not used in daily practice in Belgium.

AIM

The objective of this study (CHIPS, Captopril in Heart Insufficient Patients Study) was to compare the long-term effects of a low dose (25 mg b.i.d.) and a high dose (50 mg b.i.d.) of captopril in mild to moderate heart failure. After a titration period of at least 10 days, patients who tolerated 50 mg b.i.d., were randomly assigned to receive either the low dose or the high dose of captopril and followed up to 2 years.

RESULTS

298 patients were included and were followed up for a mean of 12 months. Progression in heart failure seems to be favourably influenced by therapy with high dose in comparison to low dose; a relative difference of 29% in the rates of heart failure worsening was observed between the two doses, 31.5% and 22.4% for low and high dose (p = 0.088), respectively. Treatment with high dose showed also a trend to benefit as compared to low dose in reducing the number of hospitalizations for all causes from 22.4 to 14.5% (p = 0.1) and for congestive heart failure from 14.7 to 7.2% (p = 0.06); moreover, the incidence of fatal and nonfatal cardiac events showed a trend in favour of the high dose of 22% (p = 0.142). The total number of adverse events was comparable for both doses, but dizziness and hypotension were a little more frequently reported in the high-dose group. Serum creatinine values showed no significant changes either in the low-dose or in the high-dose group.

CONCLUSION

In the CHIPS-study, in comparison to a low dose, therapy with a high dose of captopril tends to improve the long-term clinical outcome of patients with mild to moderate heart failure without significantly more toxicity.

Fast determination of haptoglobin phenotype and calculation of hemoglobin binding capacity using high pressure gel permeation chromatography

A new and fast method for haptoglobin (Hp) phenotyping was developed based on high pressure gel permeation chromatography of hemoglobin-supplemented serum. Haptoglobin phenotypes 1-1, 2-1, and 2-2 are resolved on the difference in size of their hemoglobin-haptoglobin complexes. Results are available in less than 15 min. Results of the chromatographic typing correspond to those obtained by conventional starch gel electrophoresis. Next to the phenotyping of haptoglobin, the method allows reproducible calculation of the hemoglobin binding capacity (HBC) of human serum. Using this methodology, reference values for HBC were found to be 0. 75+/-0.25 g/l, with the lowest HBC in Hp 2-2 subjects and the highest in Hp 1-1 subjects (P<0.05). In contrast to earlier findings, the ratio HBC:Hp concentration was found to be comparable for the three Hp types. In conclusion, this method allows a rapid phenotyping in critical clinical conditions where Hp phenotyping can be useful, e.g. determining the donor's phenotype in liver transplantation.

Off-line analysis of red blood cell velocity in renal arterioles

Videomicroscopic methods with off-line analysis of microcirculatory parameters by multifunctional computer-assisted image analysis systems have significant advantages for in vivo microvascular research. A limitation of these methods is, however, that red blood cell velocities (V(RBC)) exceeding 2 mm/s cannot be measured using standard video framing rates. In the present study, a high-speed video camera, recording up to 600 frames per second, was incorporated in the set-up, and V(RBC) was measured off-line with the line-shift-diagram method. The aim of this study was to test the reproducibility and validity of the method using a high-speed video camera and to evaluate its applicability in vivo. V(RBC) were measured in arterioles of the split hydronephrotic kidney. The intra- and interindividual variability was small for V(RBC) below 40 mm/s. The validity of the method was tested using the mass conservation principle and found to be at least as good as that of the dual-slit photometric technique. The present approach extends the application of videomicroscopy coupled to image analysis systems to the analysis of high V(RBC).

Relationship between left ventricular mass index and 24-h urinary free cortisol and cortisone in essential arterial hypertension

OBJECTIVE

Besides arterial blood pressure, nonhemodynamic factors are known to induce cardiac hypertrophy. In Cushing's syndrome, severe ventricular hypertrophy has been linked not only to increased aortic pressure, but also to elevated plasma cortisol. The aim of this study was to examine the relationship between the cortisol/cortisone levels and left ventricular mass index (LVMI) in essential arterial hypertension with and without echocardiographic left ventricular hypertrophy (LVH).

DESIGN

Eighteen untreated Caucasian patients (nine men, nine women, mean age 48+/-6 years) with essential hypertension (163+/-26/100+/-14 mm Hg) were enrolled. An age-matched control group of 13 subjects (seven men, six women) with normotension (121+/-9/79+/-7 mm Hg) were enrolled also. Left ventricular dimensions were echocardiographically assessed and cortisol production evaluated by 24-h urinary free cortisol and cortisone concentrations.

RESULTS

LVMI averaged 115+/-31 g/m2 and 24-h urinary free cortisol and cortisone were 23+/-14 microg per 24 h and 31+/-18 microg per 24 h. Prevalence of echocardiographic LVH was 56%. LVMI correlated significantly with 24-h urinary free cortisol (r = 0.61, P = 0.007) and cortisone (r = 0.60, P = 0.009). Patients with echocardiographic LVH were characterized by higher daytime ambulatory blood pressure, LVMI (particularly the posterior wall), and 24-h urinary cortisol, while office blood pressure, septal: posterior wall ratio and 24-h urinary cortisone were comparable in all patients. In control individuals, LVMI averaged 91+/-18 g/m2 and 24-h urinary free cortisol and cortisone, respectively, were 34.7+/-6.6 microg per 24 h and 64.3+/-10.8 microg per 24 h (P<0.05 versus patients). Neither LVMI nor the contributing ventricular dimensions showed significant correlation with 24-h urinary free cortisol or cortisone in the control group.

CONCLUSIONS

Our data provide evidence for a significant relationship between LVMI and cortisol production independently of arterial blood pressure in untreated mild to moderate hypertension.

Haptoglobin polymorphism and peripheral arterial occlusive disease

Haptoglobin (Hp) 2-2 phenotype is a genetic risk factor in coronary atherosclerosis. In this study, haptoglobin phenotypes were determined in 141 patients with peripheral arterial occlusive disease (PAOD) and compared to a reference population (n = 1000). The relative Hp1 allele frequency was decreased among PAOD patients (0.294 vs. 0.403 for the reference population, P < 0.01) due to an overrepresentation of the Hp 2-2 phenotype (50%, odds ratio 1.82 (95% C.I. 1.28-2.60), P < 0.001). This finding was even more pronounced in non-diabetic and in non-smoking PAOD patients (Hp1 allele frequencies: 0.265 and 0.228, respectively). Serum lipids, inflammatory parameters, and blood pressure levels were comparable among the Hp phenotypes, but serum levels of the antioxidant vitamin C were lower in Hp 2-2 patients than in patients with another phenotype (P < 0.05). In PAOD patients with severe atherosclerotic lesions, maximal walking distance of patients carrying a Hp 2-2 phenotype (225-525 m) exceeded that of other Hp phenotypes (50-242 m) (interquartile ranges) (P < 0.05). The findings demonstrate that, despite an increased risk for developing PAOD, the Hp 2-2 phenotype is associated with a longer maximal walking distance which might be attributed to the earlier reported in vitro angiogenic properties of the Hp 2-2 molecule.

Why is training effective in the treatment of patients with intermittent claudication?

Patients with peripheral arterial obstructive disease (PAOD) often have complaints of intermittent claudication. This causes a great limitation in the quality of life because of reduction in walking ability. PAOD is associated with increased morbidity and mortality. Beside other therapies, training has been shown to be an effective treatment option for patients with intermittent claudication. Exercise training significantly increases walking distance and consequently the functional behaviour of the patient. Several authors have identified different mechanisms involved in this beneficial effect. The most important are discussed in this review, namely adaptation or redistribution of the peripheral blood flow, inhibition of the progression of the atherosclerotic disease, changes in blood rheology, metabolic changes, changes in skeletal muscle morphology, economisation of walking, a change in pain perception and an effect on the cardiovascular system. It is concluded that training works through a combination of mechanisms. Further research is needed to clarify the precise mechanisms.

Reverse redistribution on thallium-201 single-photon emission tomography after primary angioplasty: a one-year follow-up study

The prognostic significance of reverse redistribution (RR) on thallium-201 single-photon emission tomography (SPET) images after acute myocardial infarction (AMI) has not been studied in detail. Moreover, RR data in patients treated with primary angioplasty are lacking. Fifty consecutive patients (including 40 men with a mean age of 54+/-11 years) with a first AMI were treated with primary angioplasty and followed up for 13+/-5 months for the following end-points: death, reinfarction and recurrent angina requiring revascularisation. Admission and peak creatine kinase myocardial enzyme (CKMB) and ejection fraction (EF) at discharge were studied as markers of myocardial damage. Thallium-201 stress-redistribution SPET studies at 1 month were analysed using a 13-segment, 4-point scoring system. Segments showing a worsening of perfusion by at least 1 point on redistribution studies were defined as showing RR. RR was present in 13 (26%) patients (group 1) and absent in 37 (74%) (group 2). Both groups were comparable for age, sex, peak CKMB release, EF and Q-wave myocardial infarctions. TIMI flow 3 was obtained in 92% in group 1 and 95% in group 2 (P = 0.95). On admission, CKMB was significantly lower in group 1 (18+/-14 vs 44+/-41 U/l, P = 0.03). Also, segments showing reversible perfusion were significantly more frequent in group 2 (1/169 vs 57/481, P = 0. 01). During follow-up, no death occurred and the combined documented endpoint of reinfarction and recurrent angina requiring angioplasty or coronary artery bypass grafting was significantly more frequently reached in group 2 (0/13 vs 10/37, P = 0.046). In conclusion, RR is common (26%) after primary angioplasty for a first AMI and is associated with lesser myocardial damage on admission. Patients with RR rarely have reversible segments on 201Tl SPET and tend to have a favourable outcome after 1 year of follow-up.

Mild to moderate hyperhomocysteinaemia in cardiovascular disease

Elevated serum levels of homocysteine, a sulphur-containing amino acid, are increasingly recognized as an independent risk factor for atherosclerotic and thrombotic vascular disease. Presence of a thermolabile variant of methylenetetrahydrofolatereductase and an inadequate folate status are the most common causes of hyperhomocysteinaemia. Homocysteine damages the vessel wall mainly through generation of oxygen radicals and creates a prothrombotic environment. In the majority of cases, normalization of homocysteine levels can be achieved with administration of vitamins of the B-group. The effect of this treatment on cardiovascular outcome, however, remains undefined.

Gallstone recurrence after successful shock wave therapy: the magnitude of the problem and the predictive factors

OBJECTIVE

Reports concerning long term recurrence of gallstones after successful extracorporeal shock wave lithotripsy (ESWL) show a high probability of stone recurrence. There is still discussion on the factors influencing stone recurrence. In this study we wanted to evaluate the long term recurrence of gallstones after stone clearance with ESWL and oral bile acids, and to assess possible risk and preventive factors of stone recurrence.

METHODS

A total of 322 consecutive patients with stone clearance between December 1988 and December 1995 were included. All patients were contacted for ultrasonography and were interviewed for additional information on daily intake of aspirin, NSAIDs, cholesterol lowering medication, estrogen therapy, and biliary pain during follow-up.

RESULTS

A total of 187 patients were still stone-free after a mean follow-up of 35 months (range: 3-89 months); 135 patients had recurrence. There was a significant association between stone recurrence and estrogen intake (p = 0.04), number of lithotripsy sessions (p = 0.0007), time until stone disappearance (p = 0.0003), and biliary pain (p < 0.0001). There was no difference in recurrence rate between solitary and multiple stones.

CONCLUSIONS

Long-term recurrence of gallstones after lithotripsy is high: < or = 69% after 6 yr. We found a significant association of stone recurrence with estrogen intake, number of lithotripsy sessions, and time until stone disappearance. Intake of aspirin or NSAIDs was not associated with decreased stone recurrence. Of the patients with recurrent stones, 57% had biliary pain.

The Selvester 32-point QRS score for evaluation of myocardial infarct size after primary coronary angioplasty

In patients treated successfully with primary angioplasty for a first myocardial infarction, the Selvester 32-point score correlates well with infarct size measured with quantitative thallium-201 perfusion imaging. Therefore, it is a useful parameter for infarct sizing, particularly in patients with anterior infarction or reduced ejection fraction at discharge.

How to study sympatho-vagal balance in arterial hypertension and the effect of antihypertensive drugs?

Blood pressure homeostasis and variability are the resultant of many complicated neurohumoral interactions. The autonomic nervous system plays a key role in the process. Since arterial hypertension is characterized by an increased sympathetic tone, the determination of the sympatho-vagal balance can give more insight in the autonomic nervous function in this pathology. The assessment of sympatho-vagal balance has been derived from reflex manoeuvres as the study of the baroreceptor function by phenylephrine or nitroglycerin test, by the application of negative or positive pressure around the neck or at the lower limbs or by tilting. Other reflex manoeuvres are hand-grip, cold pressure test, Valsalva manoeuvre, mental arithmetics and microneurography, providing information about the sympathetic reflex activity, and deep breathing about vagal reflex activity. These reflex tests have several limitations, because they request cooperation of the patient. Power spectral analysis of beat-to-beat blood pressure and RR-interval recordings permit to evaluate autonomic activity at baseline conditions and to separate the different components of variability which seem to reflect specific regulatory mechanisms. For the RR-interval, the high frequency component (HF) is a marker of vagal activity, while the low frequency component (LF) is a marker of sympathetic and vagal activity. The LF/HF ratio can be considered as a marker of sympatho-vagal balance. The significance of the LF and HF components of arterial blood pressure variability is less clear. Spectral analysis can be used to study the effect of antihypertensive drugs on sympatho-vagal balance.

Effect of haptoglobin phenotypes on growth of Streptococcus pyogenes

The haptoglobin (Hp) 2-1 and 2-2 phenotypes have been shown to agglutinate Streptococcus pyogenes carrying the membrane antigen T4. In this study, the growth rate of two strains of Streptococcus pyogenes (T1 and T4) in human serum was compared among haptoglobin phenotypes in vitro. During incubation for 16 hours in serum of different haptoglobin types, only Hp 2-1 and Hp 2-2 sera showed an inhibitory effect on growth, Hp 2-2 being 1.85 times more potent than Hp 2-1. Growth of Streptococcus pyogenes T4 negatively correlated with the serum concentration of Hp 2-1 (r = -0.908) and Hp 2-2 (r = -0.953). Haptoglobin-depleted serum had no inhibitory effect on bacterial growth. Addition of haemoglobin and ferric citrate to the serum accelerated the growth of Streptococcus pyogenes T4 (P <0.05) but not in Hp 2-2 serum. Haptoglobin types 2-1 and 2-2 can be regarded as inhibitors of Streptococcus pyogenes growth in vitro. These data point towards a potential protective role of Hp 2-2 in Streptococcus pyogenes infection in vivo, independently of iron uptake.

Haptoglobin polymorphism, iron metabolism and mortality in HIV infection

BACKGROUND

Three phenotypes of the antioxidant protein haptoglobin are known: Hp 1-1, Hp 2-1 and Hp 2-2.

OBJECTIVES

To investigate the outcome of HIV infection according to haptoglobin type.

DESIGN AND METHODS

Haptoglobin phenotypes were determined using starch gel electrophoresis in serum obtained from 653 HIV-infected Caucasians in the AIDS reference centers of Gent (n = 184), Antwerp (n = 309), and Luxembourg (n = 160). Survival was compared between haptoglobin types using Kaplan-Meier curves. Plasma HIV-1 RNA was quantified by reverse transcriptase PCR. Serum iron, transferrin saturation, ferritin, and vitamin C were assayed to evaluate iron-driven oxidative stress in 184 HIV-infected patients and 204 controls.

RESULTS

The haptoglobin type distribution amongst the patients (17.6% Hp 1-1, 49.9% Hp 2-1, 32.5% Hp 2-2) corresponded to that of the controls. Kaplan-Meier curves showed a higher mortality for the Hp 2-2 group (P = 0.0001; adjusted mortality risk ratio, 1.78; 95% confidence interval, 1.25-2.54). Median survival time was 11.0 years (Hp 1-1 and Hp 2-1) versus 7.33 years (Hp 2-2). Plasma HIV-1 RNA levels prior to antiviral therapy and their increase over 1 year were highest in Hp 2-2 patients (P = 0.03 and 0.003, respectively). The Hp 2-2 type was associated with higher serum iron, transferrin saturation, and ferritin levels and with low vitamin C concentrations. Furthermore, ferritin concentrations were higher in HIV-infected patients than in controls (P < 0.0001).

CONCLUSION

HIV-infected patients carrying the Hp 2-2 phenotype show a worse prognosis, which is reflected by a more rapid rate of viral replication (in the absence of antiviral treatment). They also accumulate more iron and oxidize more vitamin C, suggesting that less efficient protection against haemoglobin/iron-driven oxidative stress may be a direct mechanism for stimulating viral replication.

Is low serum chloride level a risk factor for cardiovascular mortality?

BACKGROUND

Serum chloride level is routinely assayed in clinical laboratories in the management of patients with kidney disorders and with metabolic diseases. It is a biological parameter that is easily, precisely and relatively cheaply measured. The epidemiological features of serum chloride levels have not been studied before.

METHODS

For the random sample of men and women from the Belgian Interuniversity Research on Nutrition and Health aged 25-74 years, free of symptomatic coronary heart disease at baseline, serum chloride concentrations were measured, among those of other electrolytes. The cohort was followed up for 10 years with respect to subsequent cause-specific mortality.

RESULTS

The results are based on observations of 4793 men and 4313 women. According to Cox regression analysis serum chloride level was one of the strongest predictors of total, cardiovascular disease (CVD) and non-CVD mortalities independently of age, body mass index, sex, smoking, systolic blood pressure, levels of total and high-density lipoprotein cholesterol, uric acid, serum creatinine and serum total proteins and intake of diuretics. This relation was proved to be independent of levels of other serum electrolytes and similar for men and women. The estimated adjusted risk ratio for CVD death for subjects with a serum chloride level < or =100 mmol/l compared with those with levels above that limit was 1.65 (95% confidence interval 1.06-2.57) for men and 2.16 (95% confidence interval 1.11-4.22) for women. The study of adjusted risk ratios for four groups of subjects defined on the basis of their baseline serum chloride levels revealed a decreasing log-linear 'dose-response' relation to total and cardiovascular mortalities.

CONCLUSION

This s the first report from a population-based study to indicate that there is an association between serum chloride level and the incidence of total, CVD and non-CVD mortalities. The risk ratio for CVD mortality associated with a low serum chloride level was comparable to or higher than those observed for well-established CVD risk factors.

Angiotensin I-converting enzyme insertion/deletion polymorphism: clinical implications

Since the identification of an Insertion/Deletion polymorphism in the ACE gene, numerous studies have evaluated the potential risk of the DD genotype in cardiovascular disease and hypertension. The report of many conflicting publications reveals a strong need for reviewing the most important data. There is evidence of the absence of an association between the ACE polymorphism and hypertension in Caucasians. In blacks a positive association between the D allele and high blood pressure was seen, Japanese studies show discrepant results. Several studies showed no association between the ACE polymorphism and the risk of myocardial infarction. However, in certain subpopulations, such as low risk patients or coronary care unit patients, an increased risk of myocardial infarction in DD type is present, and a meta-analysis supports this proposition. Because of conflicting data, the potential association between the ACE polymorphism and coronary artery disease, cerebrovascular disease, left ventricular hypertrophy, hypertrophic and idiopathic dilated cardiomyopathy, carotid artery disease and diabetic and immunoglobin A nephropathy, remains inconclusive.