Quantitative evaluation of myocardial blush to assess tissue level reperfusion in patients with acute ST-elevation myocardial infarction
Department of Cardiology, University of Heidelberg, Heidelberg, Germany. American heart journal
(Impact Factor: 4.46).
05/2007; 153(4):612-20. DOI: 10.1016/j.ahj.2006.12.019
Tissue level reperfusion gauges functional recovery in acute ischemic syndromes. However, its current clinical assessment is based upon visual interpretation of myocardial blush grade (MBG), which is operator dependent. The purpose of the study was to test whether quantification of MBG can enhance the predictive value of visual assessment for functional recovery in patients with acute ST-elevation myocardial infarction (STEMI).
Myocardial blush grade was assessed in 124 consecutive patients with STEMI visually and quantitatively, analyzing the time course of blush intensity rise. We defined Gmax as the peak gray level intensity and Tmax as the time to peak intensity. Ejection fraction >50% at 4 to 6 months of follow-up was deemed as the primary end point for assessment of successful tissue reperfusion.
Ejection fraction >50% at follow-up was predicted by visual MBG with moderate sensitivity (65%) and specificity (64%). However, a cutoff value of Gmax/Tmax = 3.1/s yielded significantly higher sensitivity and specificity (91% and 96%, respectively, for both P < .01). Gmax/Tmax was the most powerful predictor of follow-up ejection fraction >50% (relative risk of 4.6 vs 3.2 for visual MBG).
Quantitative MBG is highly predictive for functional recovery in patients with STEMI and provides incremental prognostic value to visual assessment. Thus, this simple approach may be used to gauge reperfusion strategies in acute ischemic syndromes.
- "Clinical environment, especially in case of AMI patients, does not allow the direct application of methods developed for experimental studies. Korosoglou et al.  recently published the results of a study of AMI patients proving that the computerized method for myocardial perfusion assessment is clinically feasible. Their results suggest that this low-cost measurement provides incremental prognostic value compared to the semi-quantitative visual assessment. "
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ABSTRACT: Myocardial perfusion is an important prognostic factor after recanalisation in acute myocardial infarction patients. We present a computerized, densitometric measurement method to assess myocardial perfusion on phase-matched digitally subtracted coronary angiograms.
Quantitative myocardial perfusion was assessed by the G(max)/T(max) parameter of the time-density curves (TDCs) in infarct-related myocardial regions on X-ray coronary angiograms. Arteries were masked out from regions of measurement. This novel method has been compared with enzymatic infarct size, ST-segment resolution, and ejection fraction after successful revascularization of 62 patients with acute myocardial infarction.
Significant correlations were found between G(max)/T(max) and enzymatic infarct size (R=-0.445, P<.001), ST-segment resolution (R=0.364, P=.004), and ejection fraction (R=0.278, P=.029). Bland and Altman plot of G(max)/T(max) reveals good interobserver agreement.
G(max)/T(max) of the TDC measured in the infarct-related myocardial area is a reliable parameter to assess clinical indicators of myocardial reperfusion. Therefore, results suggest that it could be used to immediately assess the success of recanalisation at the tissue perfusion level during coronary intervention, and as an objective end point in clinical trials of new interventional devices and drugs.
Available from: Sergio Finazzi
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ABSTRACT: Riassunto Premesse. L'angioplastica coronarica (PTCA) nel- l'infarto miocardio acuto (IMA) non sempre ot- tiene un'efficace riperfusione miocardica nono- stante la ricanalizzazione vascolare. Il presente studio si prefigge di esplorare, con particolare at- tenzione all'immediato post PTCA, i rapporti di NT-proBNP con variabili clinico diagnostiche pre/post procedura di impiego routinario e con riscontri angiografici di riperfusione microvasco- lare in funzione del recupero successivo della fun- zione contrattile miocardica. Materiali e Metodi. In 78 pazienti con IMA ante- riore e sopraslivellamento del tratto ST sottopo- sti a PTCA efficace sono stati misurati il parame- tro angiografico Myocardial Blush (MB) in corso di PTCA quale indice di presenza di microperfu- sione e NT-proBNP all'ingresso, a 48 ore, 7 gior- ni e a 6 mesi post procedura. I valori ecografici della frazione di eiezione ventricolare sx (FE) sono stati registrati agli stessi tempi e i parametri biochimici CK e c-TnT in basale e al picco. NT- proBNP, c-TnT e CK totale sono stati determi- nati su siero mediante analizzatore Modular PE, Roche Diagnostics, rispettivamente con tecnica ECLIA e con standardizzazione IFCC per CK. Risultati. Tranne che all'ingresso, in tutti gli altri momenti di osservazione le mediane di NT- proBNP si dimostrano significativamente inferiori nei pazienti con MB normale. All'analisi univariata sia NT-proBNP a 48 ore e a 7 giorni (OR 1.83, p = 0.004 e OR 1.62, p = 0.007, 95%CI rispettivamente) che MB sono inversamen- te correlati al recupero di FE a 6 mesi, ma MB evidenzia le migliori performance sia all'analisi univariata che multivariata. NT-proBNP a 7 giorni si correla con numerose variabili di importanza prognostica quali età, tempo di ischemia, n° vasi interessati, picco CK e c-TnT.
Available from: degruyter.com
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Invasive methods for assessment of coronary microcirculatory function are time- and instrumentation-consuming tools. Recently, novel computer-assisted videodensitometric methods have been demonstrated to provide quantitative information on myocardial (re)perfusion. The aim of the present prospective study was to evaluate the accuracy of videodensitometry-derived perfusion parameters in patients with stable angina undergoing elective coronary angiography.
The study comprised 13 patients with borderline epicardial coronary artery stenosis (40–70%). Coronary flow reserve and index of microcirculatory resistance were measured by using an intracoronary pressure and temperature sensor-tipped guidewire. A videodensitometric quantitative parameter of myocardial perfusion was calculated by the ratio of maximal density (Gmax) and the time to reach maximum density (Tmax) of the time-density curves in regions of interest on conventional coronary angiograms. Myocardium perfusion reserve was calculated as a ratio of hyperemic and baseline Gmax/Tmax.
At hyperemia a significant increase in Gmax/Tmax could be observed (p <0.0001). Significant correlations were found between myocardium perfusion reserve and coronary flow reserve (r =0.82, p =0.0008) and between hyperemic Gmax/Tmax and hyperemic index of microcirculatory resistance (r =−0.72, p =0.0058).
Videodensitometric Gmax/Tmax assessment seems to be a promising method to assess the myocardial microcirculatory state.
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