Strong cardiovascular prognostic implication of quantitative left atrial contractile function assessed by cardiac magnetic resonance imaging in patients with chronic hypertension

J Cardiovasc Magn Reson. 2011 Aug 15;13(1):42. doi: 10.1186/1532-429X-13-42.

Abstract

Background: Progressive left ventricular (LV) diastolic dysfunction due to hypertension (HTN) alters left atrial (LA) contractile function in a predictable manner. While increased LA size is a marker of LV diastolic dysfunction and has been shown to be predictive of adverse cardiovascular outcomes, the prognostic significance of altered LA contractile function is unknown.

Methods: A consecutive group of patients with chronic hypertension but without significant valvular disease or prior MI underwent clinically-indicated CMR for assessment of left ventricular (LV) function, myocardial ischemia, or viability. Calculation of LA volumes used in determining LA emptying functions was performed using the biplane area-length method.

Results: Two-hundred and ten patients were included in this study. During a median follow-up of 19 months, 48 patients experienced major adverse cardiac events (MACE), including 24 deaths. Decreased LA contractile function (LAEF(Contractile)) demonstrated strong unadjusted associations with patient mortality, non-fatal events, and all MACE. For every 10% reduction of LAEF(Contractile), unadjusted hazards to MACE, all-cause mortality, and non-fatal events increased by 1.8, 1.5, and 1.4-folds, respectively. In addition, preservation of the proportional contribution from LA contraction to total diastolic filling (Contractile/Total ratio) was strongly associated with lower MACE and patient mortality. By multivariable analyses, LAEF(Contractile) was the strongest predictor in each of the best overall models of MACE, all-cause mortality, and non-fatal events. Even after adjustment for age, gender, left atrial volume, and LVEF, LAEF(Contractile) maintained strong independent associations with MACE (p < 0.0004), all-cause mortality (p < 0.0004), and non-fatal events (p < 0.0004).

Conclusions: In hypertensive patients at risk for left ventricular diastolic dysfunction, a decreased contribution of LA contractile function to ventricular filling during diastole is strongly predictive of adverse cardiac events and death.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Atrial Function, Left*
  • Boston
  • Chronic Disease
  • Diastole
  • Disease-Free Survival
  • Electrocardiography
  • Female
  • Humans
  • Hypertension / complications*
  • Hypertension / mortality
  • Hypertension / physiopathology
  • Kaplan-Meier Estimate
  • Linear Models
  • Magnetic Resonance Imaging, Cine*
  • Male
  • Middle Aged
  • Myocardial Contraction*
  • Predictive Value of Tests
  • Prognosis
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Survival Rate
  • Time Factors
  • Ventricular Dysfunction, Left / diagnosis*
  • Ventricular Dysfunction, Left / etiology
  • Ventricular Dysfunction, Left / mortality
  • Ventricular Dysfunction, Left / physiopathology
  • Ventricular Function, Left*