Yasushi Matsuzawa1, Masaaki Konishi1, Michikazu Nakai2, Yusuke Saigusa3, Masataka Taguri4, Masaomi Gohbara5, Toshiaki Ebina1, Masami Kosuge1, Kiyoshi Hibi1, Kunihiro Nishimura6, Yoshihiro Miyamoto2, Satoshi Yasuda7, Hisao Ogawa7, Yoshihiko Saito8, Naoki Nakayama9, Ichiro Takeuchi9, Kouichi Tamura4, Kazuo Kimura1. 1. Division of Cardiology, Yokohama City University Medical Center. 2. Department of Statistics and Data Analysis, Center for Cerebral and Cardiovascular Disease Information, National Cerebral and Cardiovascular Center. 3. Department of Biostatistics, Yokohama City University. 4. Department of Data Science, School of Data Science, Yokohama City University. 5. Department of Medical Science and Cardiorenal Medicine, Yokohama City University Graduate School of Medicine. 6. Preventive Medicine and Epidemiology Informatics, National Cerebral and Cardiovascular Center. 7. Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center. 8. Department of Cardiovascular Medicine, Nara Medical University. 9. Department of Emergency Medicine, Yokohama City University Medical Center.
Abstract
BACKGROUND: Low population density may be associated with high mortality in acute myocardial infarction (AMI) patients. The purpose of this study was to investigate the effect of population density and hospital primary percutaneous coronary intervention (PCI) volume on AMI in-hospital mortality in Japan.Methods and Results: This is a retrospective study of 64,414 AMI patients transported to hospital by ambulances. The main outcome measure was in-hospital mortality. The median population density was 1,147 (interquartile range, 342-5,210) persons/km2. There was a significant negative relationship between population density and in-hospital mortality (OR for a quartile down in population density 1.086, 95% CI 1.042-1.132, P<0.001). Patients in less densely populated areas were more often transported to hospitals with a lower primary PCI volume, and they had a longer distance to travel. By using multivariable analysis, primary PCI volume was found to be significantly associated with in-hospital mortality, but distance to hospital was not. When divided into the low- and high-volume hospitals, using the cut-off value of 115 annual primary PCI procedures, the increase in in-hospital mortality associated with low population density was observed only in patients hospitalized in the low-volume hospitals. CONCLUSIONS: Increased in-hospital mortality related to low population density was observed only in AMI patients who were transported to the low primary PCI volume hospitals, but not in those who were transported to high-volume hospitals.
BACKGROUND: Low population density may be associated with high mortality in acute myocardial infarction (AMI) patients. The purpose of this study was to investigate the effect of population density and hospital primary percutaneous coronary intervention (PCI) volume on AMI in-hospital mortality in Japan.Methods and Results: This is a retrospective study of 64,414 AMI patients transported to hospital by ambulances. The main outcome measure was in-hospital mortality. The median population density was 1,147 (interquartile range, 342-5,210) persons/km2. There was a significant negative relationship between population density and in-hospital mortality (OR for a quartile down in population density 1.086, 95% CI 1.042-1.132, P<0.001). Patients in less densely populated areas were more often transported to hospitals with a lower primary PCI volume, and they had a longer distance to travel. By using multivariable analysis, primary PCI volume was found to be significantly associated with in-hospital mortality, but distance to hospital was not. When divided into the low- and high-volume hospitals, using the cut-off value of 115 annual primary PCI procedures, the increase in in-hospital mortality associated with low population density was observed only in patients hospitalized in the low-volume hospitals. CONCLUSIONS: Increased in-hospital mortality related to low population density was observed only in AMI patients who were transported to the low primary PCI volume hospitals, but not in those who were transported to high-volume hospitals.
Entities:
Keywords:
Acute myocardial infarction; In-hospital mortality; Population density