Myocardial infarction: audible fourth heart sound helped predict five year mortality.

Clinical bottom line (level 4)

A sixth of patients with a myocardial infarction were dead at 5 years.
Patients were more likely to die if they had a clearly audible S4 at one month or if they were older.

Ishikawa et al: American Journal of Cardiology 1997; 80: 619-621

Expires March 2003

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital in Japan

181 patients (aged 64 y, 76% male) acute myocardial infarction

Factors studied:

uncertain of the factors entered into the multivariate analysis
clearly audible S4 at one month (agreement on presence/absence of S4 in 99% cases)
age (10 year steps)

Multivariate logistic regression analysis was used to adjust for confounding factors.

100% followed for 56.2 months
Outcomes studied:

all cause mortality

The evidence

outcome	time to outcome	number of patients/total number	% (95% CI)
all cause mortality	56.2 months	26/181	14.4% (9.26% to 19.5%)

prognostic factor for all cause mortality	time to outcome	control rate (%)	adjusted OR (95% CI)	NNF+ (95% CI)
clearly audible S4 at one month	56 months	20/161 (12.4%)	4.29 (1.10 to 16.75)	4 (2 to 93)
age	?		1.12 (1.04 to 1.20)

Comments

The study is poorly descriptive of the factors used in multivariate analysis; the 'independence' of S4 does not describe what it is independent of!
Agreement of two cardiologists over presence of S4 was excellent.

Citation

Ishikawa M, Sataka K, Maki A, et al: Prognostic significance of a clearly audible fourth heart sound detected a month after an acute myocardial infarction. American Journal of Cardiology 1997; 80: 619-621

Contributor: Bob Phillips and Clare Wotton, November 1999
Reviewer:

_{Clinical Question.}

_Patient	_{acute myocardial infarction surviving to one-month}
_{Intervention or Exposure}	_{presence of a clear S4}
_Outcome	_{5 year mortality}