Importance of heart failure as a cause of death - Changing contribution tooverall mortality and coronary heart disease mortality in Scotland 1979-1992

Aims As heart failure is a syndrome arising from another condition, such as coronary heart disease, it is rarely officially coded as the underlying ca use of death regardless of the cause recorded by the physician at the time of certification. We sought to assess the true contribution of heart failur e to overall mortality and coronary heart disease mortality and to examine how this contribution has changed over time. Methods and Results We carried out a retrospective analysis of all death ce rtificates in Scotland between 1979 and 1992 for which heart failure was co ded as the underlying or a contributory cause of death. From a total of 833 622 deaths in Scotland between 1979 and 1992, heart failure was coded as t he underlying cause in only 1.5% (13 695), but as a contributory cause in a further 14.3% (126 073). In 1979, 28.5% of male and 40.4% of female deaths attributed to coronary heart disease (coded as the underlying cause of dea th) also had a coding for heart failure. In 1992 these percentages had rise n significantly to 34.1% and 44.8%, respectively (both P < 0.001). Mortalit y rates for heart failure as the underlying or contributory cause of death, standardized by age and sex, fell significantly over the period studied in all ages and in both sexes: by 31% in men and 41% in women <65 years and 1 5.8% in men and 5.1% in women greater than or equal to 65 years, respective ly (P < 0.01 for all changes). Conclusions Death from heart failure is substantially underestimated by off icial statistics. Furthermore, one third or more of deaths currently attrib uted to coronary heart disease may be related to heart failure and this pro portion appears to be increasing. While the absolute numbers of deaths caus ed by heart failure remains constant, this study is the first to show that standardized mortality rates are declining.