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Reliability of reported family history of myocardial infarction
572 of injury was a fall onto the slope. In comparison to skiers, snowboarders experienced 2.4 times as many fractures, particularly in the upper limb, with fractures of the wrist and forearm accounting for 35% of upper limb injuries. The rate of lower limb injuries occurred at about the same rate as with skiers, although the type of injuries differed in location, with ankle and distal tibia1 injuries being more common in snowboarding especially for novices. Skiers experienced more knee injuries (44% versus 23%). Novices wore hard-shell boots more often than more experienced riders (P < 0.001). This may explain why the novice was prone to upper limb fractures and knee injuries while the more experienced rider was prone to ankle injuries. Based on this study, the authors have recommended hybrid or soft-shell boots for the beginner as well as suitable lessons and properly fitted equipment to ensure safety. [Patrice M. Ringo, MD] Editor’s Comment: Snowboarding remains a relatively new sport with growing popularity. As a result, injuries related to snowboarding will become much more common, and physicians must be knowledgeable about related injuries.
0 INFLUENCE OF LARETALOL ON COCAINEINDUCED CORONARY VASOCONSTRICTION IN HUMANS. Boehrer JD, Moliterno DJ, Willard JE, et al. American J of Med. 1993;94:608-10. This is a prospective study that evaluated the influence of Labetalol on cocaine-induced coronary vasoconstriction. Fifteen patients (7 men and 8 women aged 40 to 79 years) who were undergoing catheterization for the evaluation of chest pain were studied. No patient admitted to previous cocaine use or received Beta-adrenergic blockers for more than 6 months prior to the study. Fifteen minutes after receiving intranasal cocaine, 2mg/kg, group 1 (n = 6) received IV normal saline while Group 2 (n = 9) received IV Labetalol, 0.25 mg/kg over 2 minutes. No change in heart rate, mean arterial pressure, or coronary arterial area was found in group 1, while mean arterial pressure fell with unchanged heart rate and coronary arterial area in group 2. The authors conclude that Labetalol reverses the cocaine-induced rise in mean arterial pressure but does not alleviate cocalne-induced coronary vasoconstriction (as measured by quantitative angiography). [Chris B. Colwell, MD] Editor’s Comment:Additional studies also have stated that Labetalol does not alleviate cocaine-induced coronary vasoconstriction. Agents that block alpha adrenergic activity may prove more useful.
0 AN INTERNATIONAL RANDOMIZED TRIAL COMPARING FOUR THRCWBOLYTIC STRATEGIES FOR ACUTE MYOCARDIAL INFARCTION. The Gusto Investigators. New Eng J of Med. 1993;329(10):673-82.
The Journal of Emergency Medione
This large scale multicenter clinical trial was designed to compare newer thrombolytic strategies with standard thrombolytic regimens in the treatment of acute myocardial infarction (MI). The study was conducted in 15 countries, 1,081 hospitals, and entered 41,021 patients. Patients included those presenting to the hospital within a 6-hour period since onset of symptoms, chest pain for at least 20 minutes, and accompanied by electrocardiographic signs of ~0.1 mV of ST segment elevation in two or more limb leads or ~0.2mV in two or more contiguous precordial leads. Patients were randomly assignedto 1 of 4 groups: (1) streptokinase with subcutaneous heparin; (2) streptokinase with intravenous heparin; (3) intravenous accelerated tissue plasminogen activator (t-PA) and intravenous heparin; and (4) intravenous accelerated t-PA, streptokinase, and intravenous heparin. The mortality rates were 7.2, 7.4, 6.3, and 7.0%, respectively. For 30-day mortality, which was the primary endpoint, there was no significant difference between the streptokinase groups (P = 0.731). There was, however, a significant reduction of 14% in mortality with accelerated t-PA as compared to the two streptokinase groups (P = 0.001). There was a significant difference between the accelerated t-PA and the combination group (P = 0.04). The rates of hemorrhagic strokes were 0.49070, 0.54070,0.72%, and 0.94%, respectively, which indicate more strokes for accelerated t-PA (P = 0.03) and the combination strategy (P < 0.001). The authors concluded that there were 10 lives saved per 1,000 treated and the prevention of death and disabling strokes in 9 patients per 1,000 treated by the thrombolytic strategy of t-PA and intravenous heparin. The advantage of this treatment regimen was attributed to survival benefit as opposed to clinical benefit and because of fewer overall allergic reactions and other [Patrice M. Ringo, MD] complications. Editor’s Comment: The t-PA advantage was particularly pronounced with anterior MIS, but it remains to be seen if this small advantage can counter the increased cost of t-PA.
0 RELIABILITY OF REPORTED FAMILY HISTORY OF MYOCARDIAL INFARCTION. Kee F, Tiret L, Robo J, et al. BMJ. 1993;307:1528-9. This case control study was conducted to assessthe reliability of reported family histories of myocardial infarction (MI). Two hundred male survivors of MI and 200 age-matched controls were interviewed at home regarding the medical histories of their first-degree relatives. For the 174 casesand 175 controls for whom a family history was obtained, the medical records and death certificates of first-degree relatives were reviewed for history of MI. A death certificate was obtained for 753 of 783 (96%) of dead relatives, and medical histories of 1,893 out of 2,029 (95 To) living relatives were verified from records or by interviewing the family physician. Among MI patients, the sensitivity, specificity, and positive predictive value of a reported history of MI in a first-degree relative was 67.3%, %.5%,
Abstracts and 70.5070,respectively. The controls did not differ significantly from the cases. [Wyatt Decker, MD] Editor’s Comment: The authors conclude that family histories of MI will miss one-third of those with affected relatives and will also overestimate the number of affected relatives by one-third.
0 DETECTION OF DEEP VENOUS THROMBOSIS: PROSPECTIVE COMPARISON OF MR IMAGING WITH CONTRAST VENOGBAPHY. Evans AJ, Sostman HD, Knelson MH, et al. Am J Radiology. 1993;161: 131-8. This is the first report of a prospective blinded study comparing magnetic resonance imaging (MRI) with contrast venography in the diagnosis of deep venous thrombosis (DVT). The authors studied 61 patients with clinically suspected DVT with both MRI and contrast venography. All images were interpreted prospectively and without knowledge of the results of the other study. The maximum time between studies was 12 hours. Twenty-one of the 61 patients were diagnosed with DVT, using contrast venography as the gold standard. MRI detected 100% of DVT located in the pelvis with a specificity of 95%. In the thigh, the sensitivity and specificity were both 100%. In the calf, the sensitivity was 87% and the specificity was 97%. The authors note that, in other studies, duplex sonography has comparable sensitivity of %% for femoral and popliteal DVT. False positive MR images resulted from rapid turbulence and flow. This problem was circumvented in some casesby the use of Cine MRI, which showed the artifact of the cardiac cycle. In equivocal cases, phase contrast MRI or femoral venography was used. No statistically significant difference between the diagnostic accuracy of MRI and contrast venography was detected. [Neil Waldman, MD] Editor’s Comment:The authors do not include the use of ultrasound in their algorithm, nor do they acknowledge the need for a different diagnostic approach for each site in the lower extremity. This study does not evaluate cost effectiveness in the use of MRI over venography or ultrasound.
[7 MYOCABDLAL INFARCT SIZE CAN BE ESTIMATED FBOM SEBLU PLASMA MYOGLOBIN MEASUBEMENTS WiTHIN 4 HOURS OF BEPEBFUSION. Yarnashita T, Abe S, Arima S, et al. Circulation. 1993;87:1840-9. This prospective study on 42 consecutive patients presenting with acute myocardial infarction to Japanese hospitals compared the estimation of infarct size by total serum myoglobin (Mb) release to that by creatinine kinase (CK) and left ventriculograms. The study was limited to left anterior descending and right coronary artery infarcts, and patients undergoing thrombolysis, percutaneous translumi-
573 nal coronary angioplasty, or both reperfusion regimens. Thirty-five patients satisfied these and other inclusion criteria. Regional hypokinesis, as determined by follow-up left ventriculography (average = 32 f 9 days), was used to assessinfarct size. The time to peak Mb concentration was 52 f 26 minutes after reperfusion, compared to 8.7 ZIZ5.3 hours for CK. Results of total Mb release (CMb) were available within 4 hours for 34 of 35 patients (mean, 132 i 40 minutes), compared to 10.3 to 46.3 hours for total CK (CCK) (mean 24.3 i 9.1 hours). The authors found that good correlation existed between CMb and CCK (r = 0.89, P < 0.001). and log CMb and ejection fraction (r = 0.71, P < 0.001). Log CMb correlated with the severity of regional hypokinesis in LAD occlusion (r = 0.88, P < 0.001) and RCA occlusion (r = -0.73; P < O.OOl), and when collaterals were absent (r = -0.93, P < 0.001) and present (r = 0.73, P < 0.01). There was no significant difference in the correlation of Mb with severity of infarct between patients receiving thrombolytics versus PTCA. The researchers conclude that serum Mb levels, collected at 15-minute intervals for 3 hours, can accurately predict severity of acute myocardial infarction within 4 hours of reperfusion. [Mark Carvalho, MD] Editor’s Comment:Patients with left circumflex lesions were excluded, as were those with renal insufficiency. Furthermore, serum Mb is not myocardial specific; thus, any diseaseprocess or medication causing skeletal muscle damage would result in an overestimation of infarct size, including electrical cardioversion. As many patients may well be on P-blockers, calcium channel blockers, antihyperlipidemics, and diuretics for co-morbid disease, the problem is not inconsequential.
0 SELECTIVE NONOPERATIVE MANAGEMENT OF PEDIATBIC BLUNT SPLENIC TRAUMA: RISK FOR MISSED ASSOCIATED INJURIES. Morse MA, Garcia VF. J Pediatr Surg. 1994;29:23-7. A retrospective chart review evaluated 129 children with blunt splenic trauma between 1982 and 1990. Falls accounted for 25.8% of the injuries. Motor-vehicle-associated trauma resulted in 58.3% of the total. Splenic injury was diagnosed by CT scan, liver/spleen scintigraphy, or during laparotomy. Fifty-nine patients had one or more associated injuries: 30 with musculoskeletal, 25 with head injury, and 22 with intra-abdominal. One hundred twelve (93.3%) were managed conservatively, with 2 (1.8%) who required delayed surgery for hemorrhage and 8 who required immediate surgery. Conservative therapy consisted of 48 to 72 hours in an intensive care unit with frequent physical examinations, serial hematocrits, and 7 to 10 days of strict bedrest. Two patients required late splenectomy for bleeding. There were no missed injuries. Morbidity and mortality were not increased due to delayed treatment. The authors concluded that most children with blunt splenic injury can be successfully treated with selective nonoperative therapy without increasing the risk of missed associated injuries. [Molly Hutsinpiller, MD]
0 INFLUENCE OF LARETALOL ON COCAINEINDUCED CORONARY VASOCONSTRICTION IN HUMANS. Boehrer JD, Moliterno DJ, Willard JE, et al. American J of Med. 1993;94:608-10. This is a prospective study that evaluated the influence of Labetalol on cocaine-induced coronary vasoconstriction. Fifteen patients (7 men and 8 women aged 40 to 79 years) who were undergoing catheterization for the evaluation of chest pain were studied. No patient admitted to previous cocaine use or received Beta-adrenergic blockers for more than 6 months prior to the study. Fifteen minutes after receiving intranasal cocaine, 2mg/kg, group 1 (n = 6) received IV normal saline while Group 2 (n = 9) received IV Labetalol, 0.25 mg/kg over 2 minutes. No change in heart rate, mean arterial pressure, or coronary arterial area was found in group 1, while mean arterial pressure fell with unchanged heart rate and coronary arterial area in group 2. The authors conclude that Labetalol reverses the cocaine-induced rise in mean arterial pressure but does not alleviate cocalne-induced coronary vasoconstriction (as measured by quantitative angiography). [Chris B. Colwell, MD] Editor’s Comment:Additional studies also have stated that Labetalol does not alleviate cocaine-induced coronary vasoconstriction. Agents that block alpha adrenergic activity may prove more useful.
0 AN INTERNATIONAL RANDOMIZED TRIAL COMPARING FOUR THRCWBOLYTIC STRATEGIES FOR ACUTE MYOCARDIAL INFARCTION. The Gusto Investigators. New Eng J of Med. 1993;329(10):673-82.
The Journal of Emergency Medione
This large scale multicenter clinical trial was designed to compare newer thrombolytic strategies with standard thrombolytic regimens in the treatment of acute myocardial infarction (MI). The study was conducted in 15 countries, 1,081 hospitals, and entered 41,021 patients. Patients included those presenting to the hospital within a 6-hour period since onset of symptoms, chest pain for at least 20 minutes, and accompanied by electrocardiographic signs of ~0.1 mV of ST segment elevation in two or more limb leads or ~0.2mV in two or more contiguous precordial leads. Patients were randomly assignedto 1 of 4 groups: (1) streptokinase with subcutaneous heparin; (2) streptokinase with intravenous heparin; (3) intravenous accelerated tissue plasminogen activator (t-PA) and intravenous heparin; and (4) intravenous accelerated t-PA, streptokinase, and intravenous heparin. The mortality rates were 7.2, 7.4, 6.3, and 7.0%, respectively. For 30-day mortality, which was the primary endpoint, there was no significant difference between the streptokinase groups (P = 0.731). There was, however, a significant reduction of 14% in mortality with accelerated t-PA as compared to the two streptokinase groups (P = 0.001). There was a significant difference between the accelerated t-PA and the combination group (P = 0.04). The rates of hemorrhagic strokes were 0.49070, 0.54070,0.72%, and 0.94%, respectively, which indicate more strokes for accelerated t-PA (P = 0.03) and the combination strategy (P < 0.001). The authors concluded that there were 10 lives saved per 1,000 treated and the prevention of death and disabling strokes in 9 patients per 1,000 treated by the thrombolytic strategy of t-PA and intravenous heparin. The advantage of this treatment regimen was attributed to survival benefit as opposed to clinical benefit and because of fewer overall allergic reactions and other [Patrice M. Ringo, MD] complications. Editor’s Comment: The t-PA advantage was particularly pronounced with anterior MIS, but it remains to be seen if this small advantage can counter the increased cost of t-PA.
0 RELIABILITY OF REPORTED FAMILY HISTORY OF MYOCARDIAL INFARCTION. Kee F, Tiret L, Robo J, et al. BMJ. 1993;307:1528-9. This case control study was conducted to assessthe reliability of reported family histories of myocardial infarction (MI). Two hundred male survivors of MI and 200 age-matched controls were interviewed at home regarding the medical histories of their first-degree relatives. For the 174 casesand 175 controls for whom a family history was obtained, the medical records and death certificates of first-degree relatives were reviewed for history of MI. A death certificate was obtained for 753 of 783 (96%) of dead relatives, and medical histories of 1,893 out of 2,029 (95 To) living relatives were verified from records or by interviewing the family physician. Among MI patients, the sensitivity, specificity, and positive predictive value of a reported history of MI in a first-degree relative was 67.3%, %.5%,
Abstracts and 70.5070,respectively. The controls did not differ significantly from the cases. [Wyatt Decker, MD] Editor’s Comment: The authors conclude that family histories of MI will miss one-third of those with affected relatives and will also overestimate the number of affected relatives by one-third.
0 DETECTION OF DEEP VENOUS THROMBOSIS: PROSPECTIVE COMPARISON OF MR IMAGING WITH CONTRAST VENOGBAPHY. Evans AJ, Sostman HD, Knelson MH, et al. Am J Radiology. 1993;161: 131-8. This is the first report of a prospective blinded study comparing magnetic resonance imaging (MRI) with contrast venography in the diagnosis of deep venous thrombosis (DVT). The authors studied 61 patients with clinically suspected DVT with both MRI and contrast venography. All images were interpreted prospectively and without knowledge of the results of the other study. The maximum time between studies was 12 hours. Twenty-one of the 61 patients were diagnosed with DVT, using contrast venography as the gold standard. MRI detected 100% of DVT located in the pelvis with a specificity of 95%. In the thigh, the sensitivity and specificity were both 100%. In the calf, the sensitivity was 87% and the specificity was 97%. The authors note that, in other studies, duplex sonography has comparable sensitivity of %% for femoral and popliteal DVT. False positive MR images resulted from rapid turbulence and flow. This problem was circumvented in some casesby the use of Cine MRI, which showed the artifact of the cardiac cycle. In equivocal cases, phase contrast MRI or femoral venography was used. No statistically significant difference between the diagnostic accuracy of MRI and contrast venography was detected. [Neil Waldman, MD] Editor’s Comment:The authors do not include the use of ultrasound in their algorithm, nor do they acknowledge the need for a different diagnostic approach for each site in the lower extremity. This study does not evaluate cost effectiveness in the use of MRI over venography or ultrasound.
[7 MYOCABDLAL INFARCT SIZE CAN BE ESTIMATED FBOM SEBLU PLASMA MYOGLOBIN MEASUBEMENTS WiTHIN 4 HOURS OF BEPEBFUSION. Yarnashita T, Abe S, Arima S, et al. Circulation. 1993;87:1840-9. This prospective study on 42 consecutive patients presenting with acute myocardial infarction to Japanese hospitals compared the estimation of infarct size by total serum myoglobin (Mb) release to that by creatinine kinase (CK) and left ventriculograms. The study was limited to left anterior descending and right coronary artery infarcts, and patients undergoing thrombolysis, percutaneous translumi-
573 nal coronary angioplasty, or both reperfusion regimens. Thirty-five patients satisfied these and other inclusion criteria. Regional hypokinesis, as determined by follow-up left ventriculography (average = 32 f 9 days), was used to assessinfarct size. The time to peak Mb concentration was 52 f 26 minutes after reperfusion, compared to 8.7 ZIZ5.3 hours for CK. Results of total Mb release (CMb) were available within 4 hours for 34 of 35 patients (mean, 132 i 40 minutes), compared to 10.3 to 46.3 hours for total CK (CCK) (mean 24.3 i 9.1 hours). The authors found that good correlation existed between CMb and CCK (r = 0.89, P < 0.001). and log CMb and ejection fraction (r = 0.71, P < 0.001). Log CMb correlated with the severity of regional hypokinesis in LAD occlusion (r = 0.88, P < 0.001) and RCA occlusion (r = -0.73; P < O.OOl), and when collaterals were absent (r = -0.93, P < 0.001) and present (r = 0.73, P < 0.01). There was no significant difference in the correlation of Mb with severity of infarct between patients receiving thrombolytics versus PTCA. The researchers conclude that serum Mb levels, collected at 15-minute intervals for 3 hours, can accurately predict severity of acute myocardial infarction within 4 hours of reperfusion. [Mark Carvalho, MD] Editor’s Comment:Patients with left circumflex lesions were excluded, as were those with renal insufficiency. Furthermore, serum Mb is not myocardial specific; thus, any diseaseprocess or medication causing skeletal muscle damage would result in an overestimation of infarct size, including electrical cardioversion. As many patients may well be on P-blockers, calcium channel blockers, antihyperlipidemics, and diuretics for co-morbid disease, the problem is not inconsequential.
0 SELECTIVE NONOPERATIVE MANAGEMENT OF PEDIATBIC BLUNT SPLENIC TRAUMA: RISK FOR MISSED ASSOCIATED INJURIES. Morse MA, Garcia VF. J Pediatr Surg. 1994;29:23-7. A retrospective chart review evaluated 129 children with blunt splenic trauma between 1982 and 1990. Falls accounted for 25.8% of the injuries. Motor-vehicle-associated trauma resulted in 58.3% of the total. Splenic injury was diagnosed by CT scan, liver/spleen scintigraphy, or during laparotomy. Fifty-nine patients had one or more associated injuries: 30 with musculoskeletal, 25 with head injury, and 22 with intra-abdominal. One hundred twelve (93.3%) were managed conservatively, with 2 (1.8%) who required delayed surgery for hemorrhage and 8 who required immediate surgery. Conservative therapy consisted of 48 to 72 hours in an intensive care unit with frequent physical examinations, serial hematocrits, and 7 to 10 days of strict bedrest. Two patients required late splenectomy for bleeding. There were no missed injuries. Morbidity and mortality were not increased due to delayed treatment. The authors concluded that most children with blunt splenic injury can be successfully treated with selective nonoperative therapy without increasing the risk of missed associated injuries. [Molly Hutsinpiller, MD]