Page 87 - Coronary hemodynamics in acute myocardial infarction - Matthijs Bax

Coronary microvascular function and long-term mortality
increase in long-term cardiac mortality hazard. The 10-year Kaplan–Meier
estimate of cardiac mortality amounted to 5% when reference CFVR was
normal and to 31% when reference vessel CFVR was abnormal. Contrariwise,
impaired CFVR measured in the infarct-related artery was not significantly associated with long-term cardiac mortality in the present data set. The acute impairment of reference vessel CFVR followed from a predominant decrease
in hyperemic APV in the presence of an increased hyperemic microvascular
resistance, in combination with a less pronounced increase in baseline APV
in the presence of a decreased baseline microvascular resistance. Persistent impairment of reference vessel CFVR at 6-month follow-up resulted from a
high baseline APV, in the presence of a low baseline microvascular resistance,
and was associated with a 10.7-fold increase in cardiac mortality hazard during subsequent follow-up. 5
Previous Studies Regarding Impaired Infarct-Related Artery CFVR and Long- term Clinical Outcome
Two studies have previously reported on the prognostic value of CFVR in the infarct-related artery. Furber et al31 described, for the first time, that Doppler flow velocity parameters in the infarct-related artery are of prognostic value for long-term cardiac events. In their study of 68 patients with a first acute MI, a short DDT in the infarct-related artery, as a parameter for impaired microvascular perfusion, was found to identify patients at high risk for cardiac events, with heart failure as the predominating cardiac event. Short DDT specifically identified those patients at risk for early occurrence of heart failure. This early differentiation in risk persisted during ≈4 years of follow-up. Additionally, a study by Takahashi et al13 evaluated the prognostic value of CFVR in the infarct-related artery on long-term cardiac events in 118 patients after primary PCI for a first anterior acute MI. They found an impaired CFVR in the infarct-related artery to be significantly associated with increased cardiac event rates at a mean of 5.2±2.7 years of follow-up. Again, impaired CFVR in the infarct-related artery was primarily shown to identify those patients at risk for early occurrence of heart failure. These studies are therefore consistent with the earlier observation that Doppler flow velocity parameters harbor accurate prognostic information on the recovery of left ventricular function.7,8,13–17
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