Coronary artery remodelling and the assessment of stenosis by pathologists

Sudden adult death

In the investigation of sudden death in adults, channelopathies, such as long QT syndrome, have risen to the fore in the minds of forensic pathologists in recent years. Examples of these disorders are touched upon in this review as an absence of abnormal findings at postmortem examination is characteristic and the importance of considering the diagnosis lies in the heritable nature of these conditions. Typically, a diagnosis of a possible channelopathy is evoked as an explanation for a 'negative autopsy' in a case of apparent sudden natural death. However, the one potential adverse effect of this approach is that subtle causes of sudden death may be overlooked. The intention of this article is to review and discuss potential causes of sudden adult death (mostly natural) that should be considered before resorting to a diagnosis of possible channelopathy. Nonetheless, it becomes apparent that many of the potential causes of sudden death can have a genetic basis. Thus, it becomes an important consideration that there may be a genetic basis to sudden death that extends beyond the negative autopsy.

Lipid-Altering Therapies and the Progression of Atherosclerotic Disease

Lipids play a key role in the progression of atherosclerosis, and lipid-lowering therapies have been studied for 30 years in coronary disease. Measurement of the progression of atherosclerosis through carotid intima-media thickness, coronary mean lumen diameter, and, mostly recently, intravascular ultrasound is generally accepted. This article reviews the role of lipid-lowering therapies in changing the rate of atherosclerosis progression in the coronary and carotid circulations. Statins are the primary therapy used to reduce atherosclerosis and cardiovascular events, including strokes and transient ischemic attacks, and have benefits in reducing events in patients undergoing carotid endarterectomy. In contrast, data for other agents, including fibrates and nicotinic acid, in reducing the progression of atherosclerosis are less extensive and not as well known. There is increasing interest in optimizing the whole lipid profile, as this might deliver extra benefits over and above statin therapy alone. Initial proof of this concept has recently come from studies that measured the progression of atherosclerosis and showed that adding nicotinic acid to statin therapy and, more directly, infusion of high-density lipoprotein-like particles reduced progression and indeed might induce regression of the disease. It is likely that the management of significant carotid stenosis will become ever more drug focused and will be customized to the lipid profile of each patient with intervention reserved only for late-stage symptomatic disease.

Association of coronary artery ectasia with plasma insulin levels in Japanese men of heterozygous familial hypercholesterolemia with the low-density lipoprotein receptor gene mutation K790X

BACKGROUND

Hyperinsulinemia is widely believed to be an important coronary risk factor. We investigated the effect of plasma insulin levels on the development of coronary ectasia in Japanese men with heterozygous familial hypercholesterolemia (FH).

METHODS

A cross-sectional study was conducted in 20 FH men with the LDL receptor mutation (K790X) [age 42.3+/-2.8 years old, body mass index (BMI) 24.6+/-0.7 kg/m2, total cholesterol (TC) 8.68+/-0.36 mmol/l, triglycerides (TG) 1.76+/-0.23 mmol/l, high-density lipoprotein cholesterol (HDL-C) 0.977+/-0.065 mmol/l]. Subjects with diabetes mellitus were excluded. Plasma insulin levels, either fasting or during oral glucose tolerance test, were compared between subjects with and without coronary artery ectasia.

RESULTS

FH subjects with coronary ectasia had significantly higher fasting plasma insulin levels than those without (12.6+/-1.4 vs. 7.7+/-0.5 mU/l; p<0.05). Also, plasma insulin levels during oral glucose tolerance test tended to be higher in the former than in the latter.

CONCLUSIONS

Plasma insulin level could be an important determinant of the development of coronary artery ectasia in Japanese heterozygous FH men.

Effect of disease eccentricity on compensatory remodeling of coronary arteries: evidence from intravascular ultrasound before interventions

BACKGROUND

Compensatory remodeling occurs to maintain lumen area in human coronary vessels. However, few data exist regarding the relationship between vessel remodeling and plaque distribution. Therefore, we studied coronary sites with or without remodeling by intravascular ultrasound and correlated with disease distribution.

METHODS AND RESULTS

A total of 90 coronary sites with significant stenosis (>50%) from 80 patients were examined before interventions. For identifying the vessel remodeling, external elastic membrane (EEM) area was measured at the stenotic sites and the adjacent proximal and distal sites. The reference EEM area was calculated by averaging proximal and distal EEM areas, and percent enlargement of the EEM area was calculated by the formula: [(stenosis EEM area-reference EEM area)/reference EEM area]x100. Plaque area was determined by reducing the lumen from EEM areas. The maximal (max) and minimal (min) distances from the center of the lumen to the EEM were also measured, and the disease eccentricity index was calculated by the formula: [(max-min)/max]. The lesion was defined as eccentric if the index was >0.5 and as concentric if <or=0.5. There were 39 eccentric and 51 concentric lesions. The enlargement remodeling was observed at 32 lesions with the enlargement of EEM area of 28.0+/-16.0% (5.5 to 71.3%). Enlargement was more frequently observed in the eccentric than in concentric lesions (P<0.05). However, within 32 stenoses, which showed enlargement, there was no difference in enlargement between eccentric (n=19, 25.6+/-21.0%) and concentric lesions (n=13, 21.5+/-12.0%). Also, there was no statistical correlation between the increase in plaque area and % enlargement of EEM area irrespective of plaque morphology.

CONCLUSIONS

These data demonstrate that in advanced coronary disease compensatory enlargement occurs more frequently at the eccentric than concentric coronary lesions. However, the EEM area was limited to expand regardless of the disease morphology.

The histologic estimation of coronary artery stenoses: accuracy and the effect of lumen shape

The authors have recently investigated the histologic estimation of coronary artery stenoses (CAS) to determine its reproducibility and the effect of training on reproducibility. The present study extends this work, examining the accuracy, the sensitivity, and the specificity of the estimation of CAS. Further, the effect of one histologic variable (i.e., arterial lumen shape) on the evaluation of CAS is examined. As described previously, 20 randomly selected Movat-stained coronary artery cross-sections were reviewed three times, at 3-month intervals, by six clinical pathologists (CPs), six pathology residents (Res), seven anatomic pathologists (APs), and two cardiovascular pathologists (CVPs). Before the third iteration, training in CAS assessment was provided. In the present study, for comparison with observer estimates, image analysis was used to establish the actual percent CAS and determine observer accuracy. The results of this study showed, paradoxically, that greater experience did not correlate with greater accuracy: The CPs consistently had the highest accuracy scores and the CVPs consistently had the lowest. Training, however, improved the accuracy scores of all groups. Stenotic arterial cross-sections with residual lumens showing concentric or eccentric polymorphous shapes were consistently underestimated compared to image analysis, while lumens with a eccentric slitlike shape were consistently overestimated.

Acp. Best practice no 155. Pathological investigation of deaths following surgery, anaesthesia, and medical procedures

The pathological investigation of deaths following surgery, anaesthesia, and medical procedures is discussed. The definition of "postoperative death" is examined and the classification of deaths following procedures detailed. The review of individual cases is described and the overall approach to necropsy and interpretation considered. There are specific sections dealing with the cardiovascular system (including air embolism, perioperative myocardial infarction, cardiac pacemakers, central venous catheters, cardiac surgery, heart valve replacement, angioplasty, and vascular surgery); respiratory system (postoperative pneumonia, pulmonary embolism, pneumothorax); central nervous system (dissection of cervical spinal cord), hepatobiliary and gastrointestinal system; musculoskeletal system; and head and neck region. Deaths associated with anaesthesia are classified and the specific problems of epidural anaesthesia and malignant hyperthermia discussed. The article concludes with a section on the recording of necropsy findings and their communication to clinicians and medicolegal authorities.