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Influence of Left Ventricular Stroke Volume on Incident Heart Failure in a Population With Preserved Ejection
Marina De Marco1, Eva Gerdts2, Costantino Mancusi3
1Hypertension Research Center, Federico II University, Naples, Italy; Department of Cardiology and Coronary Unit, Santa Maria delle Grazie Hospital of Pozzuoli, Naples, Italy.
Insights
Low stroke index (SVi), a measure of heart pump performance, independently predicts a higher risk of developing congestive heart failure (HF) in individuals with normal ejection fraction (EF). This finding highlights SVi as a crucial indicator for heart failure risk assessment.
Area of Science:
- Cardiology
- Echocardiography
- Public Health
Background:
- Left ventricular (LV) pump performance, measured by stroke index (SVi), can vary even with normal systolic function (ejection fraction [EF]).
- The predictive value of low SVi for incident heart failure (HF) in individuals with preserved EF remains unclear, particularly independent of LV geometry and function.
Purpose of the Study:
- To investigate if low SVi is an independent risk marker for incident congestive heart failure (HF) in a population with normal ejection fraction (EF).
Main Methods:
- Analysis of clinical and echocardiographic data from 2,885 American Indians in the Strong Heart Study (SHS) with normal EF (≥51% men, ≥55% women) and no prevalent HF.
- Low SVi defined as ≤22 ml/m2.04. Cox regression analysis was used to assess HF risk over a 12-year follow-up, adjusting for multiple confounders and competing risks.
Main Results:
- Low SVi was associated with lower body mass index, blood pressure, LV mass index, left atrial dimension, EF, and midwall fractional shortening (MFS), and higher relative wall thickness.
- During follow-up, 209 participants developed HF. Low SVi independently predicted a 38% higher risk of incident HF (HR 1.38; 95% CI 1.06-1.80).
- This association remained significant after adjusting for age, gender, BMI, hypertension, cardiovascular disease, LV geometry, EF, MFS, and abnormal wall motion.
Conclusions:
- In the Strong Heart Study, low stroke index (SVi) is a significant, independent predictor of incident congestive heart failure (HF) in individuals with normal ejection fraction (EF).
- SVi provides valuable prognostic information beyond traditional measures of LV geometry and systolic function, aiding in HF risk stratification.
Abstract:
At a given level of left ventricular (LV) systolic function, LV pump performance (assessed by stroke index [SVi]) may differ, depending on LV size. We evaluated whether low SVi may be considered a marker of risk for incident congestive heart failure (HF), independent of LV geometry and systolic function, assessed by ejection fraction (EF) or midwall fractional shortening (MFS), in a large population-based sample with normal EF. Clinical and echocardiographic data from the second Strong Heart Study (SHS) examination, including 2,885 American Indians (59 ± 8 years; 63% women) with normal EF (EF ≥51% in men and EF ≥55% in women) and without prevalent HF or significant valve disease, were analyzed. Low SVi was defined as SVi ≤22 ml/m2.04. Low SVi was more common among men and associated with lower body mass index, systolic blood pressure, LV mass index, left atrial dimension, EF, and MFS and with higher relative wall thickness. During a mean 12-year follow-up, 209 participants developed HF and 246 had acute myocardial infarction. In Cox regression analysis, low SVi was associated with higher risk of incident HF (hazard ratio 1.38; 95% confidence interval 1.06 to 1.80), independently of age, gender, body mass index, heart rate, hypertension, prevalent cardiovascular disease, left atrial dimension index, LV mass index, LV concentric geometry, EF or MFS, and abnormal wall motion, also accounting for myocardial infarction as a competing risk event. In conclusion, in the SHS, low SVi was associated with higher incident rate of HF, independently of LV geometry and systolic function and other major confounders.