Chronobiology of death in heart failure.
OBJECTIVE
In the general population, heart events occur more often during early morning, on Mondays, and during winter. However, the chronobiology of death in heart failure has not been analyzed. The aim of this study was to determine the circadian, day of the week, and seasonal variability of all-cause mortality in chronic heart failure.


METHODS
This was an analysis of all consecutive heart failure patients followed in a heart failure unit from January 2003 to December 2008. The circadian moment of death was analyzed at 6-h intervals and was determined by reviewing medical records and by information provided by the relatives.


RESULTS
Of 1196 patients (mean [standard deviation] age, 69 [13] years; 62% male), 418 (34.9%) died during a mean (standard deviation) follow-up of 29 (21) months. Survivors were younger, had higher body mass index, left ventricular ejection fraction, glomerular filtration rate, hemoglobin and sodium levels, and lower Framingham risk scores, amino-terminal pro-B type natriuretic peptide, troponin T, and urate values. They were more frequently treated with angiotensin receptor blockers, beta-blockers, mineralocorticoids receptor antagonists, digoxin, nitrates, hydralazine, statins, loop diuretics, and thiazides. The analysis of the circadian and weekly variability did not reveal significant differences between the four 6-h intervals or the days of the week. Mortality occurred more frequently during the winter (30.6%) compared with the other seasons (P = .024).


CONCLUSIONS
All cause mortality does not follow a circadian pattern, but a seasonal rhythm in patients with heart failure. This finding is in contrast to the circadian rhythmicity of cardiovascular events reported in the general population.
Servicio de Medicina Interna, Hospital Universitario Ramón y Cajal, Madrid, Spain; Departamento de Medicina, Universidad Autónoma de Barcelona, Barcelona, Spain. Electronic address: nribaspiza@gmail.com.
Nuria
N
Ribas
Servicio de Cardiología, Hospital Santa Creu i Sant Pau i IIB Sant Pau, Barcelona, Spain.
Maite
M
Domingo
Grupo de Investigación ICREC, Institut Germans Trias i Pujol, Badalona, Barcelona,, Spain.
Paloma
P
Gastelurrutia
Departamento de Epidemiología, Hospital Santa Creu i Sant Pau i IIB Sant Pau, Barcelona, Spain.
Andreu
A
Ferrero-Gregori
Servicio de Cardiología, Hospital Sant Pau i Santa Tecla, Tarragona, España.
Pilar
P
Rull
Servicio de Cardiología, Hospital Santa Creu i Sant Pau i IIB Sant Pau, Barcelona, Spain.
Mariana
M
Noguero
Servicio de Cardiología, Hospital Santa Creu i Sant Pau i IIB Sant Pau, Barcelona, Spain.
Carmen
C
Garcia
Departamento de Medicina, Universidad Autónoma de Barcelona, Barcelona, Spain; Grupo de Investigación ICREC, Institut Germans Trias i Pujol, Badalona, Barcelona,, Spain.
Teresa
T
Puig
Departamento de Medicina, Universidad Autónoma de Barcelona, Barcelona, Spain; Servicio de Cardiología, Hospital Santa Creu i Sant Pau i IIB Sant Pau, Barcelona, Spain.
Juan
J
Cinca
Departamento de Medicina, Universidad Autónoma de Barcelona, Barcelona, Spain; Grupo de Investigación ICREC, Institut Germans Trias i Pujol, Badalona, Barcelona,, Spain; Servicio de Cardiología, Hospital Universitari Germans Trias i Pujol, Badalona, Barcelona, Spain.
Antoni
A
Bayes-Genis
D000368:Aged; D002423:Cause of Death; D002940:Circadian Rhythm; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012621:Seasons; D013997:Time Factors
Chronobiology; Cronobiología; Heart failure; Insuficiencia cardiaca; Mortalidad; Mortality