Silent Myocardial Ischemia: From Pathophysiology to Diagnosis and Treatment.

Silent myocardial ischemia (SMI), characterized by a lack of overt symptoms despite an inadequate blood supply to the myocardium, remains a challenging entity in cardiovascular medicine. The pathogenesis involves intricate interactions of vascular, neurohormonal, and metabolic factors, contributing to perfusion deficits without the characteristic chest pain. Understanding these mechanisms is pivotal for recognizing diverse clinical presentations and designing targeted interventions. Diagnostic strategies for SMI have evolved from traditional electrocardiography to advanced imaging modalities, including stress echocardiography, single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (MRI). Treating SMI is a matter of ongoing debate, as the available evidence on the role of invasive versus medical management is controversial. This comprehensive review synthesizes current knowledge of silent myocardial ischemia, addressing its pathophysiology, diagnostic modalities, and therapeutic interventions.

Incidence, Clinical Significance, and Longitudinal Signal Characteristics of Ischemic Lesions Related to Diagnostic Cerebral Catheter Angiography.

PURPOSE: Cerebral DSA is a routine procedure with few complications. However, it is associated with presumably clinically inapparent lesions detectable on diffusion-weighted MRI imaging (DWI lesions). However, there are insufficient data regarding incidence, etiology, clinical relevance, and longitudinal development of these lesions. This study prospectively evaluated subjects undergoing elective diagnostic cerebral DSA for the occurrence of DWI lesions, potentially associated clinical symptoms and risk factors, and longitudinally monitored the lesions using state-of-the-art MRI. MATERIALS AND METHODS: Eighty-two subjects were examined by high-resolution MRI within 24 h after elective diagnostic DSA and lesion occurrence was qualitatively and quantitatively evaluated. Subjects' neurological status was assessed before and after DSA by clinical neurological examination and a perceived deficit questionnaire. Patient-related risk factors and procedural DSA data were documented. Subjects with lesions received a follow-up MRI and were questioned for neurological deficits after a median of 5.1 months. RESULTS: After DSA, 23(28%) subjects had a total of 54 DWI lesions. Significantly associated risk factors were number of vessels probed, intervention time, age, arterial hypertension, visible calcified plaques, and less examiner experience. Twenty percent of baseline lesions converted to persistent FLAIR lesions at follow-up. After DSA, none of the subjects had a clinically apparent neurological deficit. Self-perceived deficits were nonsignificantly higher at follow-up. CONCLUSION: Cerebral DSA is associated with a considerable number of postinterventional lesions, some persisting as scars in brain tissue. Presumably because of the small lesion size and inconsistent location, no clinically apparent neurological deficits have been observed. However, subtle self-perceived changes may occur. Therefore, special attention is needed to minimize avoidable risk factors.

Performance of the 2019 ESC/EASD guideline strategy for the screening of silent coronary artery disease in patients with diabetes.

BACKGROUND: The 2019 guidelines for cardiovascular risk stratification by the European Society of Cardiology and European Association for the Study of Diabetes (ESC-EASD) suggested screening for silent coronary disease in very high risk patients with severe target organ damage (TOD) (i.e. peripheral occlusive arterial disease or severe nephropathy) or high coronary artery calcium (CAC) score. This study aimed to test the validity of this strategy. METHODS: In this retrospective study, we included 385 asymptomatic patients with diabetes and no history of coronary disease but with TOD or ≥ 3 risk factors in addition to diabetes. CAC score was measured using computed tomography scan and a stress myocardial scintigraphy was performed to detect silent myocardial ischemia (SMI), with subsequent coronary angiography in those with SMI. Various strategies to select patients to be screened for SMI were tested. RESULTS: CAC score was ≥ 100 Agatston units (AU) in 175 patients (45.5%). SMI was present in 39 patients (10.1%) and among the 30 patients who underwent angiography, 15 had coronary stenoses and 12 had a revascularization procedure. The most effective strategy consisted in performing myocardial scintigraphy in the 146 patients with severe TOD and, among the 239 other patients without severe TOD, in those with CAC ≥ 100 AU: this strategy provided 82% sensitivity for SMI diagnosis, and identified all the patients with stenoses. CONCLUSION: The ESC-EASD guidelines suggesting SMI screening in asymptomatic patients with very high risk assessed by severe TOD or high CAC score appears effective and could identify all the patients with stenoses eligible for revascularization.

The role of heparin in preventing the early silent ischemia in carotid stenting.

INTRODUCTION AND AIMS: Serebral silent ischemia is a complication of carotid stenting. If silent ischemia occurs 24 h later of carotid stenting, it called early serebral silent ischemia. The aim of this study was to evaluate the effect of heparin infusion on the prevention of early silent ischemia in patients who underwent carotid stenting. MATERIALS AND METHODS: We included 26 patients who underwent carotid stenting. Patients who had carotid stenting, we randomized into two groups. The first group of patients were given continuously heparin infusion a maximum of 20,000 units for 24 h, and screened the aPTT value each 6 h. The aPTT value aimed a range of 2-3 times to up baseline. The second group didn't take heparin infusion. Diffusion weighted magnetic resonance imaging (DWI-MRI) and gradient echo (GRE) sequences performed in all patients at the 24 h of carotid stenting. RESULTS: Early serebral silent ischemia was detected by DWI-MRI in 13 (50%) of 26 patients who underwent carotid stenting. Seven (53.80%) of 13 patients whit early serebral silent ischemia did not receive heparin treatment, while 6 (46.20%) received heparin treatment. There was no symptomatic or asymptomatic acute hemorrhage in patients who treated with heparin. CONCLUSION: In our study, the continuation of anticoagulant therapy for 24 h to prevent early silent ischemia was not statistically significant. Also there is no reduction for count of serebral silent ischemia between two groups. However, due to the small number of patients in the study, future studies are required with more patients.

Assessing the prevalence and predicting factors of an abnormal gated myocardial perfusion SPECT in asymptomatic patients with type 2 diabetes.

Considering the significant prevalence of silent myocardial ischemia and its related morbidity and mortality in asymptomatic type 2 diabetic patients, it is not well known whether early screening with MPI is cost-effective and predicting factors are not well elucidated. This was a cross-sectional study including 63 asymptomatic patients with type 2 diabetes mellitus (T2DM), with normal ECG and ejection fraction. Patients with any history of documented valvular, congestive or ischemic heart disease, renal or hepatic failure were excluded. At first all patients were interviewed and checked for risk factors and then patients underwent a two-day rest/stress 99mTc-MIBI gated MPI SPECT. Data was assessed by QPS/QGS and 4DM software and evaluated by a nuclear medicine specialist with summed stress score (SSS) of more than 4 defined as CAD. There were 42 females (67%) and 21 males (33%), with a mean age of 61.33 ± 6.98 years and 7.97 ± 4.86 years history of T2DM. CAD was detected in 26 (41.3%) patients and was significantly associated with male gender, smoking and requiring insulin therapy (P-value = 0.019, 0.046, 0.05, respectively). A significant association was found between the duration of diabetes, especially when > 15 years, and the probability of having CAD. Multivariable logistic regression revealed that smoking; male gender and diabetes duration were the strongest independent predictors of abnormal MPI results. We found a high (46%) prevalence of abnormal stress MPI SPECT in patients with type 2 diabetes mellitus, despite being asymptomatic. Asymptomatic patients with a history of smoking, long duration of diabetes, being under insulin treatment and male gender might benefit from MPI for early detection of silent ischemia.

Resting Left Ventricular Global Longitudinal Strain to Identify Silent Myocardial Ischemia in Asymptomatic Patients with Diabetes Mellitus.

BACKGROUND: Screening for silent coronary artery disease in asymptomatic patients with diabetes mellitus (DM) is challenging and controversial. In this context, it seems crucial to identify early markers of coronary artery disease. METHODS: The aim of this study was to investigate the incremental value of resting left ventricular (LV) global longitudinal strain (GLS) for the prediction of positive results on stress (exercise or dobutamine) transthoracic echocardiography in 273 consecutive asymptomatic high-risk patients with DM. Positive results on stress transthoracic echocardiography were defined as stress-induced LV wall motion abnormalities (new or worsening preexisting abnormalities). RESULTS: Compared with patients with negative stress results, those with positive stress results (n = 28 [10%]) more frequently had cardiovascular risk factors, complications of DM, vascular disease, moderate and severe calcification of the aortic valve and mitral annulus, and worse resting LV GLS (-16.7 ± 2.9% vs -19.0 ± 1.9%, P < .001). On multivariable logistic regression analysis, DM duration > 10 years, diabetic retinopathy, LV hypertrophy, and impaired LV GLS (odds ratio, 1.39 [95% CI, 1.14-1.70] per percentage increase; odds ratio, 5.16 [95% CI, 1.96-13.59] for LV GLS worse than -18%) were independently associated with positive results on stress transthoracic echocardiography. The area under the curve to predict positive results was 0.74 for LV GLS with a cutoff of -18.0% (sensitivity 68%, specificity 78%). The area under the curve of the multivariable model to predict test results was improved by the addition of LV GLS (P < .001), with a bias-corrected area under the curve after bootstrapping of 0.842 [95% CI, 0.753-0.893]. CONCLUSIONS: The present findings show that resting LV GLS is associated with the presence of silent ischemia and could be useful to better identify asymptomatic patients with DM who might benefit from coronary artery disease screening.

Burden of arrhythmia and silent ischemia in heart transplant patients with cardiac allograft vasculopathy.

BACKGROUND: The incidence of sudden cardiac death (SCD) following heart transplantation (HTx) accounts for approximately 10% of post-HTx deaths. Ischemia, brady- and tachy-arrhythmias caused by rejection and cardiac allograft vasculopathy (CAV) seem related to SCD. Hence, we aimed to investigate the relation between CAV, arrhythmias and silent ischemia in long-term HTx patients. Methods. 49 HTx patients were included. Patients were CAV classified in accordance with guidelines from the International Society of Heart and Lung Transplantation. Patients were divided into predefined CAV groups (CAV 0, CAV 1, CAV 2 + 3). Incidences of arrhythmia and silent ischemia were detected by 48-h electrocardiogram monitoring and analyzed blinded to CAV-status. Results. Median time since transplantation was 9 years [IQR 4-14]. We observed a higher incidence of non-sustained ventricular tachycardia (NSVT) in CAV 2 + 3 patients than CAV 0 and 1 patients (p = .01). Likewise, isolated premature ventricular complexes (PVC) (p = .01) and PQ-interval prolongation (p = .01) were more frequent in CAV 2 + 3 patients than CAV 0 and 1 patients. Silent ischemia was only observed among CAV 3 patients (p = .04). We saw no significant difference in the incidence of supraventricular tachycardia among CAV groups (p = .21). Likewise, no difference in the right bundle branch block was observed (p = .68). Conclusion. NSVT was associated with CAV status in long-term HTx patients. Patients with moderate to severe CAV showed higher incidences of PVCs and PQ-interval prolongation than patients with mild or no CAV. Silent ischemia was only seen in patients with severe CAV.

Diabetes and the Risk of Sudden Cardiac Death.

PURPOSE OF REVIEW: Persons with diabetes mellitus (DM) have increased morbidity and mortality rates compared with persons without DM. Sudden cardiac death (SCD) is a leading cause of death, and multiple studies have found an increased risk of SCD among individuals with DM. This review sought to collect the latest knowledge of the epidemiological and pathophysiological interplay between DM and SCD. RECENT FINDINGS: Persons with DM have a two- to tenfold increased risk of SCD compared with persons without DM. The underlying mechanisms for the increased risk of SCD are complex and multifactorial. The main pathophysiological contributors are DM-induced cardiac autonomic neuropathy (CAN), metabolic changes, silent ischemia, and polypharmacy. Persons with DM have an increased risk of SCD. Future studies should focus on CAN and the combined risk of QT prolongation from the interplay between CAN, hypoglycemia, and polypharmacy. Genes and pathways involved in control of the autonomic nervous system and cardiac ion channels could be a future focal point.

Simulation Training in Neuroangiography: Transfer to Reality.

PURPOSE: Endovascular simulation is an established and validated training method, but there is still no proof of direct patient's benefit, defined as lower complication rate. In this study, the impact of such a training was investigated for rehearsal of patient-specific cases as well as for a structured simulation curriculum to teach angiographer novices. MATERIALS AND METHODS: A total of 40 patients undergoing a diagnostic neuroangiography were randomized in a training and control group. In all training group patients, the angiographer received a patient-anatomy-specific rehearsal on a high-fidelity simulator prior to the real angiography. Radiation exposure, total duration, fluoroscopy time and amount of contrast agent of the real angiography were recorded. Silent cerebral ischemia was counted by magnetic resonance diffusion-weighted imaging (DWI). Additionally, the first 30 diagnostic neuroangiographies of six novices were compared (ntotal = 180). Three novices had undergone a structured simulation curriculum; three had acquired angiographic skills without simulation. RESULTS: No differences were found in the number of DWI lesions or in other quality measures of the angiographies performed with and without patient-specific rehearsal. A structured simulation curriculum for angiographer novices reduced fluoroscopy time significantly and radiation exposure. The curriculum had no influence on the total duration of the examination, the amount of contrast medium or the number of catheters used. CONCLUSION: There was no measurable benefit of patient-anatomy-specific rehearsal for an unselected patient cohort. A structured simulation-based curriculum to teach angiographic skills resulted in a reduction of fluoroscopy time and radiation dose in the first real angiographies of novice angiographers. LEVEL OF EVIDENCE: Level 4, part 1: randomized trial, part 2: historically controlled study.

Ambulatory and silent myocardial ischemia in women with coronary microvascular dysfunction: Results from the Cardiac Autonomic Nervous System study (CANS).

BACKGROUND: Up to two-thirds of patients with obstructive coronary artery disease (CAD) have silent ischemia (SI), which predicts an adverse prognosis and can be a treatment target in obstructive CAD. Over 50% of women with ischemia and no obstructive CAD have coronary microvascular dysfunction (CMD), which is associated with adverse cardiovascular outcomes. We aimed to investigate the prevalence of SI in CMD in order to consider it as a potential treatment target. METHODS: 36 women with CMD by coronary reactivity testing and 16 age matched reference subjects underwent 24-h 12-lead ambulatory ECG monitoring (Mortara Instruments) after anti-ischemia medication withdrawal. Ambulatory ECG recordings were reviewed by two-physician consensus masked to subject status for SI measured by evidence of ≥1 minute horizontal or downsloping ST segment depression ≥1.0 mm, measured 80 ms from the J point. RESULTS: Demographics, resting heart rate, and systolic blood pressure were similar between CMD and reference subjects. Thirty-nine percent of CMD women had a total of 26 SI episodes vs. 0 episodes in the reference group (p = 0.002). Among these women 13/14 (93%) had SI, and few episodes (3/26, 12%) were symptomatic. Mean HR at the onset of SI was 96 ±â€¯13 bpm and increased to 117 ±â€¯16 bpm during the ischemic episodes. 87% reported symptoms that were not associated with ST depressions. CONCLUSIONS: Ambulatory ischemia is prevalent in women with CMD, with a majority being SI, while most reported symptoms were not accompanied by ambulatory ischemia. Clinical trials evaluating anti-ischemic medications should be considered in the CMD population.

Risk of undiagnosed coronary artery disease associated with infrapopliteal artery occlusion from a multicenter study.

Peripheral artery disease (PAD) is associated with high cardiovascular mortality. Which part of PAD with lower extremities is related to coronary artery disease (CAD) remains unknown. We hypothesized that PAD including infrapopliteal artery (IPA) occlusion was associated with CAD. A total of 260 patients who have no history of CAD or the anginal symptom, complain of the claudication or critical limb ischemia and underwent peripheral angiography were retrospectively analyzed. IPA occlusion was diagnosed with peripheral angiography, and CAD was diagnosed with the coronary angiography. A multivariate logistic regression analysis was performed to determine the predictors of silent CAD. Among them, a total of 146 patients (56.2%) had IPA occlusion. Baseline characteristics were significantly different between two groups as to the proportions of age, male, dyslipidemia (with vs. without IPA occlusion; 72.4 ± 10.8 vs. 69.1 ± 10.2; 62.3% vs. 75.4%; 38.6% vs. 52.6%, respectively, all comparisons P < 0.05). Notably, the prevalence of CAD was significantly higher in patients with IPA occlusion (50.7% vs. 34.2%, P = 0.008). On a multivariate analysis, IPA occlusion was an independent predictor for the presence of silent CAD (OR, 1.94; CI, 1.09-3.44, P = 0.024), but aortoiliac artery occlusion (OR, 1.16; CI, 0.53-2.56, P = 0.71) and femoropopliteal artery occlusion (OR, 1.02; CI, 0.57-1.83, P = 0.96) were not. IPA occlusion was associated with silent CAD. Vascular surgeons, interventional radiologists, as well as interventional cardiologists should recognize IPA occlusion as a risk factor of silent CAD.

Cardiac Autonomic Neuropathy in Diabetes Mellitus.

Cardiovascular autonomic neuropathy (CAN) is a severely debilitating yet underdiagnosed condition in patients with diabetes. The prevalence can range from 2.5% (based on the primary prevention cohort in the Diabetes Control and Complications Trial) to as high as 90% of patients with type 1 diabetes. Clinical manifestations range from orthostasis to myocardial infarction. The diagnosis is made using multiple autonomic function tests to assess both sympathetic and parasympathetic function. The pathophysiology of CAN is complex, likely multifactorial, and not completely understood. Treatment is limited to symptomatic control of orthostatic hypotension, which is a late complication, and current strategies to reverse CAN are limited. This review explores the epidemiology, pathophysiology, clinical manifestations, diagnosis, and complications of CAN as well as current treatment options.

Predictors and prognostic impact of silent coronary artery disease in asymptomatic high-risk patients with diabetes mellitus.

AIMS: Evaluation of predictors of silent coronary artery disease (SCAD) in high-risk asymptomatic diabetic patients and to evaluate their two-year outcome. METHODS AND RESULTS: Four hundred diabetic patients without prior CAD but at high CAD risk underwent myocardial perfusion scintigraphy (MPS) in this prospective multicentre outcome trial. MPS were abnormal in 22% of patients. Male sex (OR 2.223, 1.152-4.290; p=0.017), diabetes duration (OR 1.049,1.015-1.085; p=0·005), peripheral artery disease (OR 2.134, 1·150-3.961; p=0.016), smoking (OR 2.064, 1.109-3.839; p=0·022), systolic blood pressure (OR 1.014, 1.00-1.03, p=0·056), brain natriuretic peptide (OR 1.002, 1.001-1.004, p=0·005) independently predicted an abnormal MPS: if <2 and >3 predictors were present, 3.2% and 47% patients had an abnormal MPS, respectively (p<0·001). Two-year major adverse cardiac event rates increased from 2·9% to 14·6%, cardiac death rates from 0·6% to 4·1% in patients with summed stress scores ≤10 and >10%, respectively (each p<0.045). CONCLUSIONS: Male sex, diabetes duration, peripheral artery disease, smoking, elevated systolic blood pressure and increased brain-natriuretic peptides independently predicted SCAD. In presence of >3 predictors, almost 50% of patients had an abnormal MPS. They may benefit from screening by MPS since the extent of the MPS abnormality discriminated clearly between a favourable compared to a bad 2-year outcome. However, even highest risk patients without objective evidence of CAD had a benign prognosis without need for specific evaluation or therapy. TRIAL REGISTRATION NUMBER: ISRCTN87953632.

An unusual cause of myocardial ischemia: Compression of a left internal mammary artery grafting to the left anterior descending artery by a pacemaker lead.

An 83-year-old patient, with prior history of coronary artery disease treated by coronary-artery bypass graft with left internal mammary artery (LIMA) to the left anterior descending artery (2001) and angioplasty of the right coronary artery (2012) and prior pacemaker through left subclavian vein (2014), was referred to coronary angiography for an anterior silent ischemia. It found no evolving lesion on the native coronary artery network (compared with 2012 review) but revealed an external compression of the LIMA bridge by the pacemaker lead. Conservative treatment was chosen rather than explantation and reimplantation of stimulus material or LIMA angioplasty. .

[Comparative Study Of Coronary Artery Disease In Diabetics And Non-Diabetics In The Department Of Cardiology Of Aristide Le Dantec University Hospital]. / Etude Comparative De La Maladie Coronaire Chez Les Diabétiques Et Non Diabétiques Au Service De Cardiologie Du CHU Aristide Le Dantec.

The aim of this study was to compare the features of coronary artery disease between diabetic and non-diabetic patients. PATIENTS AND METHODS: A case-control study was carried out from 1 May 2013 to 31 July 2015 in the department of cardiology of Aristide le Dantec university hospital. Forty-five diabetic patients and forty-five non-diabetic patients who underwent coronary angiography and / or angioplasty were included. RESULTS: There was a male predominance with a sex ratio of 1.6 in both groups. The mean age was 62.26 years for diabetics and 59.06 years for non-diabetics (p = 0.6). In diabetics, symptomatology was dominated by silent ischemia (48.9%) versus typical angina pain (68.9%) in non-diabetics. Myocardial infarction was the most common indication of coronary angiography in both groups. Coronary angiography revealed one-vessel disease (46.6% versus 41.7% p = 0.822), double vessel disease (26.7% versus 41.7% p = 0.091) and triple vessel disease (26.7% versus 16.6% p = 0.561). Angioplasty was indicated in 37.8% of diabetics versus 63.9% of non-diabetics. Nine diabetic patients and three non-diabetic patients had an indication of coronary artery bypass grafting. CONCLUSION: Our study confirms the greater frequency of silent ischemia and multiple-vessel disease in diabetics as well as a more frequent indication of coronary artery bypass grafting in these patients.

L'objectif de cette étude était de comparer les aspects de la maladie coronaire entre les patients diabétiques et non diabétiques. PATIENTS ET MÉTHODES: Une étude cas-témoins a été réalisée du 1er mai 2013 au 31 juillet 2015 au service de cardiologie du CHU Aristide le Dantec. Quarante cinq patients diabétiques et 45 patients non diabétiques ayant bénéficié d'une coronarographie et/ou d'une angioplastie avaient été inclus. RÉSULTATS: Nous avions retrouvé une prédominance masculine avec un sex ratio de 1,6 dans les deux groupes. L'âge moyen était de 62,26 ans pour les diabétiques et de 59,06 ans pour les non diabétiques (p=0,6). Chez les diabétiques, la symptomatologie était dominée par l'ischémie silencieuse (48,9%) et la douleur angineuse typique (68,9%) chez les non diabétiques. L'infarctus du myocarde était l'indication de la coronarographie la plus fréquente dans les deux groupes. La coronarographie retrouvait respectivement chez les diabétiques et non diabétiques une atteinte mono-tronculaire (46,6% versus 41,7% p=0,822), une atteinte bi-tronculaire (26,7% versus 41,7% p=0,091) et une atteinte tri-tronculaire (26.7% versus 16,6 % p=0,561). Une angioplastie avait été indiquée chez (37,8%) des diabétiques et (63,9%) des non diabétiques. Neuf patients diabétiques et trois patients non diabétiques avaient eu une indication de pontage coronaire. CONCLUSION: Notre étude confirme une plus grande fréquence de l'ischémie silencieuse et de l'atteinte multi tronculaire chez les diabétiques ainsi qu'une indication plus fréquente de pontage aorto coronaire.

Ambulatory monitoring of myocardial ischemia in the 21st century-an opportunity for high frequency QRS analysis.

Ambulatory monitoring represents an effective tool for the assessment of silent and transient myocardial ischemia during routine daily activities. Incidence of silent ischemia can provide important prognostic information about patients with coronary artery disease or acute coronary syndrome, as well as about post-myocardial infarction patients. The current technological progress enables development of powerful and miniaturized wearable devices for Holter monitoring. Higher sampling rates, dynamic range, and extended computational and storage capacity allow for considering of more complex methodological solutions such as high-frequency QRS analysis for diagnosing myocardial ischemia. Implementation of suitable methodologies for advanced detection of myocardial ischemia into modern ambulatory monitoring devices creates the potential of making the ambulatory myocardial ischemia monitoring a valuable diagnostic tool in clinical practice.

The defense response and alcohol intake: A coronary artery disease risk? The SABPA Study.

The behavioral defense coping response (DefS) as a measure of coping with emotional stress may increase alcohol intake (gamma glutamyl transferase (γGT)), the risk for coronary artery disease (CAD) and insulin sensitivity (homeostasis model assessment, HOMA). We assessed associations between coping and cardiometabolic risk markers in a bi-ethnic cohort (N = 390) from South Africa. Ambulatory blood pressure (BP) and ECG, fasting blood and coping scores were obtained. Africans, and mostly when utilizing DefS, showed higher 24h BP, a low-grade inflammatory state, central obesity, increased HOMA [4.07 (3.66, 4.47)] and more ST events compared to their Caucasian counterparts. ROC γ-GT analyses predicting 24-h ambulatory hypertension showed a higher γ-GT cut-point in Africans (55.4 U/l) than in Caucasians (19.5 U/l). Odds ratios (ORs) of γ-GT cut-points predicting 24-h ambulatory hypertension was evident in DefS African men [OR: 7.37 (95% CI: 6.71-8.05), p = 0.003] and in DefS Caucasians, albeit at a lower γ-GT cut-point (19.5 U/l). Higher γ-GT cut-points in DefS Africans or Caucasians were not associated with HOMA > 3. DefS accompanied by alcohol abuse in taxing emotional situations, if no social support is forthcoming, underscores a profile of reduced coronary perfusion. It may enhance vasoconstriction of the coronary arteries, with compensatory increases in BP, and induce a risk for future coronary artery disease.

Fibrosis and coronary perfusion - a cardiovascular disease risk in an African male cohort: The SABPA study.

Low-grade inflammation has been correlated with risk factors of cardiovascular diseases (CVD). Whether the pro-inflammatory and thrombotic ratio (fibrosis) may contribute to CVD is not known. We therefore aimed to assess whether Cornell Product left ventricular hypertrophy (LVH) is associated with fibrosis and coronary perfusion (silent ischemia) in a bi-ethnic male cohort from South Africa. A cross sectional study was conducted including 165 African and Caucasian men between the ages of 20-65. Fasting blood samples were obtained to measure fibrinogen, C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α). Ambulatory blood pressure, ECG and 12 lead ECG measures were obtained to determine silent ischemic events (ST events) and LVH, respectively. Africans revealed more silent ischemia, higher 24 h blood pressure, inflammatory, coagulation as well as fibrosis levels than Caucasians. In a low-grade inflammatory state (CRP > 3 mg/l), Africans revealed higher fibrosis (p ≤ 0.01) values, but lower IL-6 and TNF-α values than Caucasians. Linear regression analyses in several models demonstrated positive associations between silent ischemia and fibrosis [Adj. R(2) 0.23; ß 0.35 (95% CI 0.13, 0.58), p ≤ 0.01]. In a low-grade inflammatory state (CRP>3mg/l), fibrinogen predicted AV-block in African men [OR 3.38 (95% CI 2.24, 4.53); p = 0.04]. Low-grade inflammation may induce AV-block through mechanisms involving fibrosis and ischemia to increase the burden on the heart in African men.