Changes in acute myocardial infarction risk and patterns of practice for patients older and younger than 70 years, 1987-90.
OBJECTIVE
To evaluate temporal changes in risk and patterns of hospital practice for acute myocardial infarction (AMI).


METHODS
Retrospective analysis of age-related medical therapy and outcome of 342 consecutive patients (132 at least 70 years old and 210 younger than 70) with AMI between July 1, 1989, and June 30, 1990, and comparison with data from two previous analyses of AMI practice in 1987 (n = 207) and 1988-89 (n = 402).


METHODS
Tertiary care medical centre.


METHODS
No direct interventions; results of the two previous AMI practice pattern analyses, however, were propagated during the practice time of the most recent analysis.


RESULTS
In 1989-90, hospital mortality was higher (19%) among patients at least 70 years old compared with patients younger than 70 (8%) (P less than 0.01). Therapies proven by repeated clinical trials to be effective in reducing AMI risk were all used less frequently in patients aged at least 70 years: thrombolysis (20 versus 43%); beta-blockers (41 versus 62%); acetylsalicylic acid (71 versus 87%); and nitrates (86 versus 97%). Qualitatively, these age-specific patterns of AMI mortality and therapy were similar to previous studies. Quantitatively, however, comparing 1987 with 1989-90 demonstrated parallel and marked increases in the use of all proven medications in both age groups, ranging from 42 to 230% (P less than 0.01). There was also a significant overall decrease in mortality from the 1987 patient cohort (20%) to the 1989-90 cohort (13%) (P less than 0.05). The decrease in mortality was entirely due to decreased mortality within the group 70 years or older; 35% in 1987 versus 19% in 1989-90 (P less than 0.05). Mortality in the AMI patients younger than 70 years old remained unchanged from 1987 to 1989-90.


CONCLUSIONS
Pattern of practice analyses were associated with, and may have contributed to, improved patient care and outcomes in AMI. Increased use of effective AMI medical therapy had a greater benefit in elderly higher risk AMI patients than lower risk younger patients. Persisting age-specific differences in AMI therapy may respond to more direct quality improvement measures, such as critical path management.
Montague
T J
TJ
Epidemiology Coordinating and Research (EPICORE) Centre, University of Edmonton, Alberta.
Wong
R Y
RY
Burton
J R
JR
Bay
K S
KS
Catellier
D J
DJ
Teo
K K
KK
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000416:Alberta / Q000453:epidemiology; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001241:Aspirin / Q000627:therapeutic use; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D004502:Education, Medical, Continuing / Q000592:standards; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy / Q000453:epidemiology / Q000401:mortality; D009566:Nitrates / Q000627:therapeutic use; D010818:Practice Patterns, Physicians' / Q000592:standards* / Q000639:trends; D012189:Retrospective Studies; D012737:Sex Factors; D015912:Thrombolytic Therapy / Q000592:standards; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D009566:Nitrates; D001241:Aspirin