Age and sex-specific reference ranges of left ventricular strain rates and cardiovascular outcomes: the Copenhagen City Heart Study.

BACKGROUND

Left ventricular (LV) strain rates assessed by two-dimensional speckle-tracking echocardiography have exhibited clinical and prognostic significance but remain sparsely used.

OBJECTIVES

We sought to establish age and sex-based normative values of LV strain rates and to assess the prognostic yield of lower limits of normality (LLN).

METHODS

LV strain rate parameters included global systolic strain rate (GSRs), global early diastolic strain rate (GSRe) and global late diastolic strain rate (GSRa). The primary population consisted of healthy participants free of risk factors from the Copenhagen City Heart Study. The prognostic yield of LLN was assessed against a composite endpoint of cardiovascular death, incident heart failure and acute myocardial infarction using Cox regression in a secondary validation population, regardless of health status.

RESULTS

The healthy population consisted of 1930 subjects with a median age of 46 years (IQR 33, 58), of whom 1193 (61.8%) were female. Median values were -0.97 s-1 (IQR -1.07, -0.90) for GSRs, 1.43 s-1 (1.17, 1.70) for GSRe and 0.77 s-1 (0.60, 0.93) for GSRa. Normative values were determined according to sex and four age intervals. All three parameters differed across sexes, while GSRs was negatively correlated with heart rate; GSRe and GSRa were negatively and positively correlated with age, respectively. GSRa below the sex- and age-appropriate LLN was independently associated with a higher risk of the composite outcome.

CONCLUSION

This is the largest study to report sex- and age-specific normal values for LV strain rates. The LLNs identified, namely for GSRa, provided independent prognostic information regarding adverse cardiovascular events.