Determinants and effects of microvascular obstruction on serial change in left ventricular diastolic function after...

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Myocardial Infarction Research

Background:

• Left ventricular (LV) diastolic dysfunction impacts functional capacity post-acute myocardial infarction (AMI).
• Determinants of LV diastolic functional changes after reperfused AMI are not fully understood.
• Microvascular obstruction (MVO) is a potential factor influencing these changes.

Purpose of the Study:

• To investigate the impact of microvascular obstruction (MVO) on mid-term changes in LV diastolic function.
• To identify sensitive indices of diastolic function recovery after reperfused AMI.
• To compare diastolic function changes in patients with and without MVO.

Main Methods:

• A cohort of 72 patients with reperfused AMI underwent serial echocardiography and cardiovascular magnetic resonance imaging at 9-month intervals.
• Assessed parameters included late gadolinium enhancement (LGE), LV and left atrial (LA) phasic functions, mitral inflow, and tissue Doppler measurements.
• Evaluated LV ejection fraction (LVEF), LV global longitudinal strain (GLS), mitral inflow deceleration time (DT), and LV elastance index (Ed).

Main Results:

• 43% of patients had MVO. Both LV ejection fraction and LV global longitudinal strain improved significantly over 9 months, with a decrease in LGE.
• Mitral inflow deceleration time and LV elastance index showed significant improvement, unlike conventional diastolic functional indexes.
• Improvements in these diastolic parameters were less pronounced in patients with MVO compared to those without.
• LGE amount and LVEF changes correlated with improvements in LV-Ed and LA function, not conventional diastolic indexes.

Conclusions:

• Deceleration time of early mitral inflow, phasic left atrial function, and LV elastance index are sensitive measures of diastolic function post-reperfusion.
• The recovery of these diastolic parameters is less prominent in patients with microvascular obstruction.
• MVO negatively affects mid-term diastolic functional recovery after reperfused AMI.