Clinical Profile, Management, and Outcome in Patients With Out-of-Hospital Cardiac Arrest and ST Segment Elevation Myocardial Infarction: Insights From a 20-Year Registry

AIM OF THE STUDY

We studied the clinical profile, management, and outcomes of patients with out-of-hospital cardiac arrest (OHCA) with and without ST-elevation myocardial infarction (STEMI).

METHODS

Retrospective analysis of the 20-year registry data (January 1991- June 2010) was conducted on patients with cardiac disease hospitalized at Hamad General Hospital and Qatar Heart Hospital, Doha, Qatar.

RESULTS

A total of 987 patients with OHCA were admitted to the cardiology department during the study period; among them, 296 (30%) patients had STEMI. Compared to the patients with OHCA without STEMI, the patients who had OHCA with STEMI were younger (53 ± 13 vs 58 ± 16 years; P = .001), more likely to be male (78% vs 34%; P = .001), smokers (35% vs 14%) but less likely to have hypertension (30% vs 48%; P = .001), diabetes (32% vs 47%, P = .001), and chronic renal failure (3.4% vs 9%; P = .002). The use of thrombolytic treatment in patients with STEMI increased from 21.6% (period 1991-1095) to 44.4% (period 2006-2010); P = .04.

CONCLUSION

Percutaneous coronary intervention had increased significantly during the last quarter of the study. There was a decline in the in-hospital mortality among patients with STEMI during the last quarter of the study.

Abstracts “From Qatar to the World”

Background: Ocular trauma is a significant problem in pediatric patients. Also, leads to visual loss throughout the world there are no data of pediatric ocular trauma in Arabian Gulf Countries in the current literature.

Aim: To study the epidemiology, mechanism, causes and outcome of serious ocular trauma requiring hospital admission, in children below 16 years of age.

Study design: A retrospective cohort study. Subjects: All pediatric patients (up to 16 years of age) presenting with ocular injuries to a tertiary care pediatric ophthalmology and Pediatric Accident Emergency Department January 1, 2005 to December 30,2009.

Abstracts from Other Journals

Relapse prevention with antipsychotic drugs compared with placebo in patients with schizophrenia has not been sufficiently addressed by previous systematic reviews. We aimed to assess the association between such drugs and various outcomes in patients with schizophrenia to resolve controversial issues.

Clinical presentation and cardiovascular risk profiles in patients with left main coronary artery disease in a middle eastern country

We evaluated the prevalence and clinical profile of patients with left main coronary artery disease (LMCA) in Qatar between 2006 and 2010. Patients were divided into 2 groups: patients with LMCA and patients without LMCA but had severe 3-vessel disease (VeD) eligible for surgical revascularization. Among 7000 patients who underwent coronary angiography, 210 patients had significant LMCA and 200 patients with severe 3VeD were matched for age and sex. Diabetes mellitus and hypertension were comparable in the 2 groups. Presentations with myocardial infarction or heart failure were comparable in both groups. Isolated LMCA was 4-fold higher in women (P = .02). Dyslipidemia and smoking were more prevalent in patients with distal and proximal lesions, respectively. Renal failure was independent predictor of LMCA (adjusted odds ratio: 2.6; 95% confidence interval: 1.43-4.69). One-year mortality was higher in LMCA (P = .01). The LMCA carries high mortality. Certain cardiovascular risk factors were important predictors of stenosis site.

Abstracts from Other Journals 2

Background: Early detection and treatment of Hepatitis C can change the natural history of disease.

Aim: The primary aim of this study was to detect infection of hepatitis C using a rapid immunochromatographic assay in a community setting. The secondary aims included assessment of prevalence rate and disease characteristics; including liver function tests, viral load, grade and stage of disease on the liver biopsy.

Methods: Two cohorts of 4000 and 321 2 people (.004% of the population) were surveyed over a three week period each between December 2008 through August 2009. Qualitative detection of hepatitis C antibodies was done using a colloidal gold enhanced rapid immunochromatographic assay (Health Chem Diagnostics LLC, FL-USA).Viral load was calculated using RT PCR (Taqman) and those found positive underwent liver biopsy.28 and 33patients with proven chronic hepatitis C formed the controls for validation of the kit used in the first and the second cohort.

Abstracts from Other Journals 1

Background: Cellular and animal studies suggest that hypercholesterolemia contributes to Alzheimer disease (AD). However, the relationship between cholesterol and dementia at the population level is less clear and may vary over the lifespan.

Methods: The Prospective Population Study of Women, consisting of 1,462 women without dementia aged 38–60 years, was initiated in 1968–1969 in Gothenburg, Sweden. Follow-ups were conducted in 1974–1975, 1980–1981, 1992–1993, and 2000–2001. All-cause dementia was diagnosed according to DSM-III-R criteria and AD according to National Institute of Neurological and Communicative Disorders and Stroke, Alzheimer's Disease, and Related Disorders Association criteria. Cox proportional hazards regression examined baseline, time-dependent, and change in cholesterol levels in relation to incident dementia and AD among all participants. Analyses were repeated among participants who survived to the age of 70 years or older and participated in the 2000–2001 examination.

Selected Abstracts From Other Journals

Background: Since some patients with psoriatic arthritis do not respond to typical drug treatments, alternatives are needed. Findings suggest that interleukins 12 and 23 might affect clinical symptoms and pathological joint changes of psoriatic arthritis. Ustekinumab is a human monoclonal antibody that inhibits receptor-binding of these cytokines. We aimed to assess the efficacy and safety of ustekinumab for psoriatic arthritis in this phase II study.

Assessment of Initiation Time of Thrombolytic Therapy in Patients with ST-Segment Elevation Myocardial Infarction in Hamad General Hospital

The elevation of reperfusion therapy for acute STsegment elevation myocardial infarction are time-related and there are decreasing benefits with increasing delays to therapy. To determine whether the time interval between a patient's arrival at the emergency department of Hamad General Hospital, Qatar and initiation of thrombolytic therapy in the coronary care unit (door-to-needle time) is within the 30 minutes recommended by American College of Cardiology!American Heart Association guidelines, the medical records were reviewed of 213 patients with STsegment elevation myocardial infarction who were admitted through the Emergency Department to receive thrombolysis in the Coronary Care Unit in the twelve months May 2006-April 2007. Medians were calculated for door-to-needle and painto-needle times and intermediate points. The median painto-needle and pain-to-door times were 211 and 143 minutes respectively, both increasing significantly with the age of the patient and were shorter in men than in women. The median door-to-needle time was 60 minutes with 11.7% of the sample having a door-to-needle time within the recommended 30 minutes. It is concluded that the need for transferring such patients from the emergency department to the coronary care unit of the hospital before the administration of thrombolysis incurs inevitable delays that can be minimized by administering thrombolysis in the emergency department.

Selected Abstracts From Other Journals

Background: We aimed to investigate whether the addition of nonsteroidal anti-inflammatory drugs or spinal manipulative therapy, or both, would result in faster recovery for patients with acute low back pain receiving recommended first-line care.

“From Qatar to the World” Abstracts Presented at International Conferences lor Published in Medical Journals

Objective: To review the incidence of ruptured uteri at the Women's Hospital, Hamad Medical Corporation (HMC) and to analyze the causative factors of uterine rupture with the view to its prevention and to highlight the management approach taken to preserve the patient's reproductive potential.

Evidence-Based Medicine: An Overview

Knowledge is the corner stone of teaching, and this is built upon by reading. The word “doctor” in Latin means, “to teach”. Hence reading comes with the difficulty of selecting the appropriate material. What to read and how to read? There are more than 65,000 medical articles published each day, and it is impossible to keep up-to-date by reading them all (which could take 40 years). So, one needs to be highly selective in reading by applying the first rule in evidence-based medicine; PICO (Population, Intervention, Comparability and Outcome of the study)

Catheter-Induced Left Main Coronary Artery Spiral Dissection: Stenting or Bypass? (Case Report and Literature Review)

Catheter-induced Left Main Coronary Artery (LMCA) dissection is a very uncommon but life-threatening complication of coronary intervention and requires urgent management. We report one such patient whose risk factors appear to be Coronary Artery Disease (CAD), smoking and a prior Myocardial Infarction (MI).

Selected Abstracts From Other Journals

Contex: In assessing the patient with headache, clinicians are often faced with 2 important questions: Is this headache a migraine? Does this patient require neuroimaging? The diagnosis of migraine can direct therapy, and information obtained from the history and physical examination is used by physicians to determine which patients require neuroimaging.

“From Qatar to the World” Abstracts Presented at International Conferences lor Published in Medical Journals

Aim: To assess the exocrine pancreatic function among cystic fibrosis patients with cystic fibrosis trans-membrane conductance regulator (CFTR) 11234V mutation. METHODS: Cross-sectional study of 40 cystic fibrosis patients with homozygous CFTR 11234V mutation belonging to a large Arab kindred family and 25 healthy subjects as a control group over a period of 12 mo. Assessment of their exocrine pancreatic function was performed by measuring faecal elastase-1 (FE1) concentration with a commercial ELISA kit using polyclonal antibodies (BioServ Diagnostics) in CF patients compared to healthy subjects. The results were compared with those obtained from a second laboratory using another commercial ELISA (ScheBo; Biotech, Germany) that uses two monoclonal antibodies against different specific epitopes of human pancreatic elastase. RESULTS: All CF patients with CFTR 11234V mutation had normal levels of faecal elastase 1. No significant difference was found between the two methods for the CF groups or between the CF patients with and without pancreatic enzyme replacement.

Epilepsy and Women: A difficult combination!

Epilepsy is one of the commonest neurological disorders with increasing incidence over the last few decades.

As with many neurological disorders, the incidence of the disease is slightly higher in females than males and certain measures or precautions have to be addressed by the treating Physician(s) when treating females with epilepsy as failure to do so my involve medico-legal implications.

Chromosomal Analysis in a Sample of Iraqi Children with Down's Syndrome and Concominant Cogenital Heart Disease

To study the demographical pattern of Iraqi children with Down's syndrome (DS) and congenital heart disease (CHD) forty-five children with DS were examined clinically, radiologic ally and by 2D color Doppler echocardiography. In eight with CHD (six female, two male) chromosomal analysis was used to investigate the possible relationship between chromosomal patterns and the type of CHD. All had a 47,+21 chromosomal pattern. Three had atrioventricular septal defect (AVSD), three atrial septal defect (ASD) and two ventricular septal defect (VSD). Only one case had reached the Eisenmenger complex, all the others had pulmonary hypertension. In this small sample of Iraqi children with Down's syndrome there appeared no relationship between CHD type and chromosomal pattern.

“From Qatar to the World” Abstracts Presented at International Conferences /or Published in Medical Journals

Objectives: to estimate the prevalence and determinants of lower urinary tract symptoms (LUTS), in male expatriate workers in Qatar and to assess the impact of LUTS on the quality of life (Qol).

Selected Abstracts From Other Journals

Context: A history of depression may increase risk for developing Alzheimer disease (AD) later in life. Clarifying this relation might improve understanding of risk factors for and disease mechanisms in AD.

Digitalis Toxicity and Fab Fragment

This article presents a brief overview of digitalis toxicity, class of medication that is notoriously know for its toxicity, but which still has significant use in clinical practice. We hereby briefly outline on the use of digoxin specific Fab fragment in the treatment of digitalis toxicity

Carpal Tunnel Syndrome

Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers (although not the little finger), as well as impulses to some small muscles in the hand that allow the fingers and thumb to move. The carpal tunnel - a narrow, rigid passageway of ligament and bones at the base of the hand 3/4 houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed. The result may be pain, weakness, or numbness in the hand and wrist, radiating up the arm. Although painful sensations may indicate other conditions, carpal tunnel syndrome is the most common and widely known of the entrapment neuropathies in which the body's peripheral nerves are compressed or traumatized.

Selected Abstracts From Other Journals

Background: A consensus has emerged that angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-II receptor blockers (ARBs) have specific renoprotective effects. Guidelines specify that these are the drugs of choice for the treatment of hypertension in patients with renal disease. We sought to determine to what extent this consensus is supported by the available evidence.

“From Qatar to the World” Abstracts

Diagnostic procedures performed on patients with multiple myeloma typically reveal lytic bone lesions, osteopenia or osteoporosis, bone marrow infiltration by plasma cells as well as overproduction of immunoglobulin or light chains in the serum or urine. Skeletal manifestations are extremely variable and the unusual forms have been described extensively. Extramedullar plasma-cell tumours (plasmocytoma) are found in about 5% of newly diagnosed patients with multiple myelomas. In this paper we present eight patients with atypical forms of multiple myeloma.

Does the circadian pattern for acute cardiac events presentation vary with fasting?

BACKGROUND

Over one billion Muslims fast worldwide during the month of Ramadan. The impact of fasting on circadian presentation with acute cardiac events is unknown.

AIM

To determine if fasting has any effect on the circadian presentation of acute cardiac events.

SETTING AND DESIGN

A prospective study in a general hospital.

MATERIALS AND METHODS

Patients with acute coronary events were divided into two groups based on the history of fasting. Information about age, gender, cardiovascular risk factor profiles and outcome was collected. The relationship of time of presentation of initial symptoms with fasting was evaluated using Student's t-test, Mann-Whitney U-test and chi2 analysis.

RESULTS

Of the 1019 patients hospitalized during the study period, 162 were fasting. Although, fasting patients were more likely to present to the emergency department in the time periods 5-6 AM (10.5% vs 6.3%) and 11 PM (11.1% vs 7.1%) and were less likely to present in the time periods 1-2 PM (3.7% vs 7.2%) and 5-6 PM (3.7% vs 7.0%); these differences were not statistically significant. Fasting patients were less likely to have their symptoms start between 5 and 8 AM (11.1% vs 19.4%) and more likely to have symptoms between 5 and 6 PM (11.1% vs 6.0%) and 3 and 4 AM (11.1% vs 6.9%). These differences for time of initial symptoms were statistically significant (P=0.002).

CONCLUSION

Exogenous factors associated with fasting, namely, the changes in food intake and/or sleep timings, affect the circadian rhythm and influence the timing of presentation of acute coronary events.

(First Available Description of Circulation) Ibn Al Nafis Original Manuscript and Translation

“And this is the right one of the two Cavities of the heart. If blood was to be “purified” in these cavities, it must pass to the left cavity where the “soul” is generated, but there are no passages between the two cavities. The mass of the heart here is dull and has no visible apertures, as some people wrongly thought. In fact, there are no invisible openings suitable for the passage of blood, either as Galen wrongly thought. The cavities of the heart in this region are sealed and its mass is thick. Therefore, if is necessary that blood to be “purified” it has to pass through the “ARTERIAL VEIN” to the lungs where it penetrates into its mass, mixes with air, and the better part of it is “purified”. It then passes into the “VENOUS ARTERY” to reach the left cavity of the heart.”

Pulse Oximetry: A Useful Tool

The principal advantage of optical sensors for medical applications is their intrinsic safety since there is no electrical contact between the patient and the equipment. Pulse oximetry is a simple, continuous, non-invasive method of monitoring the percentage of haemoglobin (Hb) which is saturated with oxygen. Oxygen saturation (Sa02) is defined as the ratio of oxygen content of hemoglobin over oxygen carrying capacity. A pulse oximeter consists of two light-emitting diodes, a photocell detector and a microprocessor with a visual display unit. The unit displays the percentage of Hb saturated with oxygen together with a signal that is audible for each pulse beat, a calculated heart rate and in some models, a graphical representation of the blood flow past the probe. An oximeter gives early warning of hypoxic events.

Ximelagatran, the Oral Anticoagulant of the Future An Evidence Based Review

This article presents the available data on Ximelagatran, a novel oral direct thrombin inhibitor and explores its therapeutic potential Recent large clinical trials have evaluated the efficacy and safety of this anticoagulant compared to the standard anticoagulation therapy with warfarin and heparins in several thrombotic disorders. These trials provide strong evidence for the efficacy and safety of ximelagatran in the following clinical indications; the prevention of venous thromboembolism after knee or hip replacement, the treatment of deep venous thrombosis, and prevention of stroke in patients with atrial fibrillation. Further evaluation of this promising oral anticoagulant is warranted in other thrombotic cardiovascular disorders requiring chronic oral anticoagulation therapy such as in patients with prosthetic heart valves, intracardiac thrombi, dilated cardiomyopathy, after myocardial infarction and post percutaneous coronary interventions.

Selected Abstracts From Other Journals

Background: Although capacities for intensive monitoring of patients with stroke are still limited, patients at risk for early neurologic worsening are poorly defined.

Insight into the New Changes in European Resuscitation Council Guidelines for Adult Resuscitation (2005)

It is five years now since the last European resuscitation guidelines were published(1). The science of resuscitation has been enriched with further significant scientific evidence that has led to new evidence-based guidelines. These guidelines were released in November 2005 and published in the international Journal of Resuscitation, November 2005(2).

“From Qatar to the World” Abstracts Presented at International Conferences /or Published in Medical Journals

Objective: The management of antenatally diagnosed ureteropelvic junction obstruction (PUJO) is controversial. Here, we present our experience over a period of 13 years and discuss our management protocol.

Materials and Methods: We received the files of 234 patients with antenatally diagnosed congenital hydronephrosis due to PUJO. Management was tailored to each patient, based on a combination of diethylenetetraminepentacetic acid renogram outcome, pelvic diameter, as well as the patient's symptoms.

Selected Abstracts From Other Journals

Context: There is a paucity of effective, well-tolerated drugs available for migraine prophylaxis.

Objective: To determine whether treatment with the angiotensin II receptor blocker candesartan is effective as a migraine-prophylactic drug.

Design and Setting: Randomized, double-blind, placebo-controlled crossover study performed in a Norwegian neurological outpatient clinic from January 2001 to February 2002.

Patient: Sixty patients aged 18 to 65 years with 2 to 6 migraine attacks per month were recruited mainly from newspaper advertisements.

Interventions: A placebo run-in period of 4 weeks was followed by two 12-week treatment periods separated by 4 weeks of placebo washout. Thirty patients were randomly assigned to receive one 16-mg candesartan cilexetil tablet daily in the first treatment period followed by 1 placebo tablet daily in the second period. The remaining 30 received placebo followed by candesartan.

Epidemiology of Breast Cancer in Qatar 1999-2002

This is retrospective study of breast cancer in Qatar during period 1999-2002, using cancer registry data A total 214 patients were diagnosed with breast cancer; with incidence of5/10,000 of population per year; account-ing for 13.3% of new cancer cases and 29.9% of all female cancer. Male breast cancer is rare accounting for 3.2% of total number. Qatari patients were 23% and non-Qatari patients were 36.2%. The disease more common in ages between 46-55years old accounting for 64% of total breast cancer; patients usually presented beyond or equal to Stage II and with distant metastasis in 7% of cases, patients com-monly present with invasive ductal carcinoma and histo-logical Grade 2 & 3, it has been noticed that were decrease in incidence of Stage III & IV and decrease in Stage I & II which reflect improvement in patient awareness of this problem.

G6PD Deficiency

G6PD deficiency is the most common enzyme deficiency disease worldwide, affecting 10% of the world's population. It is an X linked recessive disease therefore it affects males more than females (females are usually carriers of the disease).

Tutorials in Therapeutics Should Cholesterol Level be lowered below “Normal”?: Insights from the Heart Protection Study

The benefits of cholesterol-lowering with statins has been established for patients with high cholesterol levels as well as for patients with prior occlusive coronary heart disease. However; substantial uncertainty has existed about the long-term benefits of these agents in certain groups, including patients with “normal” cholesterol levels pretreatment, women, the elderly, as well as those with prior occlusive non-coronary disease. The Heart Protection Study 1 was designed to resolve these uncertainties and to provide substantially more safety information of statins. We present its significance and practical implications.

Oxygen - Hemoglobin Dissociation Curve

The delivery system of oxygen in the human body consist of lungs and CVS, which it depends by it self on the:

Peripheral Nerve Injuries

Peripheral nerve injuries are one of the usual spotter cases in international exams. They are fun to diagnose and can be easily identified by knowing many of the characteristic signs and tests. A few basic concepts in the anatomy, course and branches of the peripheral nerves makes it possible to diagnose the level of lesion with ease.

Updates in Pediatrics Basic Life Support:An Evidence-Based Review

The American Heart Association, together with representatives from the International Liaison Committee on Resuscitation (ILCOR), which is made up of leading resuscitation organizations from the Americas, Europe, Southern Africa, Australia, and New Zealand, undertook a series of evidence-based evaluations of the science of resuscitation which culminated in the publication of ’Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care’ in August 2000 tL2). Experts from non-ILCOR organizations from Asia and elsewhere also participated in drawing up the guidelines.

Resuscitation Guidelines Updates: Adult Advanced Life Support

The International Guidelines 2000 Conference on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care was the world's first international conference to produce evidence- based international resuscitation guidelines.

Selected Abstracts From Other Journals

Objective: To define forces of youth soccer ball heading (headers) and determine whether heading causes retinal hemorrhage.

Setting: Regional Children's Hospital, youth soccer camp.

Patients: Male and female soccer players, 13 to 16 years old, who regularly head soccer balls.

Measurements: Dilated retinal examination, after 2-week header diary, and accelerometer measurement of heading a lofted soccer ball.

Results: Twenty-one youth soccer players, averaging 79 headers in the prior 2 weeks, and 3 players who did not submit header diaries lacked retinal hemorrhage. Thirty control subjects also lacked retinal hemorrhage. Seven subjects heading the ball experienced linear cranial accelerations of 3.7±1.3g. Rotational accelerations were negligible.

Conclusions: Headers, not associated with globe impact, are unlikely to cause retinal hemorrhage. Correctly executed headers did not cause significant rotational acceleration of the head, but incorrectly executed headers might.

Acute Anterior Myocardial Infarction Following Electrocution

Electrocution is a well known cause of cardiac arrest, mostly secondary to ventricular fibrillation. Acute myocardial infarction has been reported in a few cases although the pathogenesis is not clear. We report two cases of acute myocardial infarction after electrocution, both confirmed by electrocardiography and markedly elevated cardiac enzymes. Echocardiography showed cardiac damage evidenced by hypokinesia.

Selected Abstracts From Other journals

Background: The analgesics used for pediatric tonsillectomy may be associated with side-effects such as sedation, respiratory depression and vomiting (opiods) or increased bleeding [non-steroidal anti inflammatory drugs (NSAIDs)]. In our institution, we employ a combination of paracetamol, NSAID and opioid, although there is no published evidence of analgesic benefits from adding NSAIDs to paracetamol in children.

Resuscitation Guidelines Update: Adult Basic Life Support

The International Guidelines 2000 Conference on Cardiop-ulmonary Resuscitation and Emergency Cardiovascular Care was the world's first international conference to produce evi-dence-based international resuscitation guidelines.

Herein, we summarize the changes in these guidelines as it applies to Adult Basic Life Support (BLS). This interpretation is basically similar to that of the European Resuscitation Coun-cil (ERC). The changes have been incorporated into the cur-riculum of our Advanced Life Support (ALS) provider courses and the new 2001 ERC ALS manual.

From Qatar to the World” Abstracts Presented at International Conferences

This study aimed to investigate the effect of oral pilocarpine (OP) in reducing the incidence of chemotherapy-induced oral mucositis. Thirty two adult patients completed a total of 82 courses of chemotherapy in which either OP or placebo was given pro-phylactically in a double-blind cross-over design to prevent mucositis. Mucositis was documented in 20 out of 41 courses in which patients were given placebo, whereas mucositis was documented in only six out of 41 courses when patients were given OP (P<0.005). OP treatment was found to significantly reduce the mucositis score when assessed by the method of Donnelly and colleagues (Donnelly JP, Muus P, Schatttenberg A, De Witte T, Horrevorts A, De Pauw BE. Bone Marrow Transplant 1992, 9, 409–413). Using this score, all patients scored a total of 52 when they were given the placebo versus eleven when they were treated with OP (P<0.001). A similar reduction in mucositis score was noticed using the World Health Organization (WHO) mucositis score; the total patient score was 25 for the placebo-treated group versus 6 for the OP group (PcO.OOl). We therefore conclude that oral pilocarpine is highly effective in the prevention of oral mucositis when given prophylactically to adult patients receiving a variety of cancer chemotherapy regimens

Myocardial infarction with normal coronary angiography compared with severe coronary artery disease without myocardial infarction: the crucial role of smoking

BACKGROUND

Why do some patients suffer acute myocardial infarction (MI) despite angiographically normal coronary arteries (NL + MI) whereas others enjoy an acute MI-free life despite extensive three-vessel disease (3VD-MI)? The present study contrasts these two groups to identify some differences in the risk profile.

METHODS

In 10,000 patients admitted to the cardiology service, a first MI was confirmed in 2356 patients, of whom 1609 underwent coronary angiography. In 77 patients with MI, coronary angiography was found to be entirely normal (NL + MI, 77/1609, 4.1%). These were contrasted to 123 patients with severe three-vessel coronary disease but no MI (3VD-MI).

RESULTS

Patients with NL + MI were 13 years younger (42 +/- 8.3 vs 55 +/- 10.5, P < 0.05), with 33 patients (43%) under the age 40 years, in contrast to only 9 patients (7.3%) in the 3VD group being this age. Patients with NC + MI were more often current smokers (80.5% vs 29% in the 3VD group; P < 0.01). Patients with 3VD-MI were, on the other hand, more often diabetic (54% vs 9% in the NL + MI group; P < 0.01) and had a higher cholesterol level (5.6 +/- 1.1 vs 4.9 +/- 1.0 Mmol/l, P < 0.01) as well as a higher incidence of chronic stable angina (52% vs 22%; P < 0.01) and heart failure (6% compared with 0% in the NL + MI group). Sixty-one out of 77 (79%) NL + MI patients had a single risk factor, and in 87%, this was smoking alone. Diabetes mellitus was rare and never occurred alone in this group.

CONCLUSION

In patients who suffer MI despite normal coronary angiography, smoking is a major risk factor: In contrast, in patients with extensive coronary artery disease on angiography but no MI, diabetes rather than smoking is the dominant risk factor. The findings of this study support the view that the risk factors for stable and unstable coronary artery disease are different, as reflected by the contrast of the above groups at the extremes of the spectrum. Smoking appears to be a major risk factor for acute MI (even with normal coronary angiography), whereas diabetes is a major risk factor for more severe but more stable coronary artery disease.

Can rotational atherectomy cause thermal tissue damage? A study of the potential heating and thermal tissue effects of a rotational atherectomy device

PURPOSE

Thermal tissue damage (TTD) is customarily associated with some lasers. The thermal potential of rotational atherectomy (RA) devices is unknown. We investigated the temperature profile and potential TTD as well as the value of fluid flushing of an RA device.

METHODS

We used a high-resolution infrared imaging system that can detect changes as small as 0.1 degree C to measure the temperature changes at the tip of a fast RA device with and without fluid flushing. To assess TTD, segments of porcine aorta were subjected to the rotating tip under controlled conditions, stained by a special histochemical stain (picrisirius red) and examined under normal and polarized light microscopy.

RESULTS

There was significant heating of the rotating cam. The mean "peak" temperature rise was 52.8 +/- 16.9 degrees C. This was related to rotational speed; thus the "peak" temperature rise was 88.3 +/- 12.6 degrees C at 80,000 rpm and 17.3 +/- 3.8 degrees C at 20,000 rpm (p < 0.001, t-test). Fluid flushing at 18 ml/min reduced, but did not abolish, heating of the device (11.8 +/- 2.9 degrees C). A crater was observed in all segments exposed to the rotating tip. The following features were most notable: (i) A zone of "thermal" tissue damage extended radially from the crater reaching adventitia in some sections, especially at high speeds. This zone showed markedly reduced or absent birefringence. (ii) Fluid flushing of the catheter reduced the above changes but increased the incidence and extent of dissections in the media, especially when combined with high atherectomy speeds. (iii) These changes were observed in five of six specimens exposed to RA without flushing, but in only one of six with flushing (p < 0.05). (iv) None of the above changes was seen in control segments.

CONCLUSION

RA is capable of generating significant heat and potential TTD. Fluid flushing reduced heating and TTD. These findings warrant further studies in vivo, and may influence the design of atherectomy devices.

Fast rotating atherectomy catheter tip inhibits platelet aggregation and ATP release: a study using platelet-rich plasma

The interaction of atherectomy devices with the arterial wall is the focus of many studies, but their effect on the surrounding blood is largely unknown. This is a detailed investigation on the effects of a rotational atherectomy device with a fast rotating tip on platelet structure and function. Platelet-rich plasma (PRP) was obtained from six volunteers, divided into 5 mL samples, and subjected to the atherectomy tip rotating at 20, 40, or 80 thousand rpm for 30 or 60 seconds. Platelet aggregation to collagen or adenosine diphosphate (ADP) was obtained in all samples by means of a dual-chamber optical aggregometer. The fast rotating catheter tip caused marked inhibition of platelet aggregation to both collagen and ADP. The maximum extent of aggregation was reduced from 85% +/-2.8 in control to 46% +/-4.8 with collagen (p<0.01) and from 86.1% +/-6.9 to 25.1% +/-4.3 with ADP (p<0.01). The rate of aggregation (measured at 4 minutes) dropped from 81.3% +/-2.7 to 40% +/-4.5 and from 73.9% +/-8.5 to 12.5% +/-2.6 (p<0.005) with collagen and ADP, respectively. These effects were related to rotating speed and duration of exposure. ATP release in response to collagen fell from 2.63 +/-0.13 nMol in control to 0.7 +/-0.1 nMol, p<0.001 after exposure to the rotating tip. There was no significant change in platelet count, nor was there formation of platelet aggregates (platelet aggregate ratio remained unchanged) to account for these phenomena. Furthermore, transmission electron microscopy showed no significant platelet disruption or release of granules, and little signs of activation were seen even after addition of collagen. This is the first study to demonstrate that exposure to a fast rotating catheter tip inhibits in vitro platelet aggregation and ATP release. There were no apparent loss of integrity of platelet structure, release of granules, or formation of platelet aggregates. This phenomenon and its clinical implication justify further investigation.

Coronary angiography in Qatar: the first ten years

Cardiac catheterization in Qatar was initiated in July 1982. In ten years, a total of 3900 procedures were performed at Hamad General Hospital. Computerized data registry has been maintained since 1982. Isolated coronary angiography was done in 2911 patients; of these, 2635 (90.5%) were men, and 276 (9.5%) were women, the average age of the patients was 47+/-9.2 years (range, twenty-five to eighty-eight). Patients' nationality was Qatari in 492 (17%), and other Arabs in 610 (21%), and 1512 (52%) were from the Asian subcontinent. Myocardial infarction was the most common indication (43%). Single-vessel disease was found in 638 (22%), two-vessel disease in 630 (22%), three-vessel disease in 950 (33%), and nonsignificant coronary artery disease in 693 (24%) patients. Morbidity related to the coronary angiography was reported in 147 (5%) patients, but there was no mortality related to the procedure. In 822 (28%) patients, the age was forty years or younger. The angiographic findings of these younger patients were compared with those of the older ones. Younger patients were usually men of Asian subcontinental origin with a recent myocardial infarction (MI). Often, they had normal coronary arteries or single-vessel disease. Patients of Asian subcontinent origin were usually young male patients with a recent MI, who receive streptokinase, and have single-vessel disease.