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Impact of Heart Rate on Myocardial Salvage in Timely Reperfused Patients with ST-Segment Elevation Myocardial Infarction: New Insights from Cardiovascular Magnetic Resonance.

Arcari L, Cimino S, De Luca L, Francone M, Galea N, Reali M, Carbone I, Iacoboni C, Agati L - PLoS ONE (2015)

Bottom Line: MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001).High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium.In particular, salvaged myocardium significantly reduced when heart rate at presentation is ≥85 bpm.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Sapienza University of Rome, Rome, Italy.

ABSTRACT

Background: Previous studies evaluating the progression of the necrotic wave in relation to heart rate were carried out only in animal models of ST-elevated myocardial infarction (STEMI). Aim of the study was to investigate changes of myocardial salvage in relation to different heart rates at hospital admission in timely reperfused patients with STEMI by using cardiovascular magnetic resonance (CMR).

Methods: One hundred-eighty-seven patients with STEMI successfully and timely treated with primary coronary angioplasty underwent CMR five days after hospital admission. According to the heart rate at presentation, patients were subcategorized into 5 quintiles: <55 bpm (group I, n = 44), 55-64 bpm (group II, n = 35), 65-74 bpm (group III, n = 35), 75-84 bpm (group IV, n = 37), ≥85 bpm (group V, n = 36). Area at risk, infarct size, microvascular obstruction (MVO) and myocardium salvaged index (MSI) were assessed by CMR using standard sequences.

Results: Lower heart rates at presentation were associated with a bigger amount of myocardial salvage after reperfusion. MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001). Stepwise multivariable analysis showed heart rate, peak troponin and the presence of MVO were independent predictor of myocardial salvage. No changes related to heart rate were observed in relation to area at risk and infarct size.

Conclusions: High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium. In particular, salvaged myocardium significantly reduced when heart rate at presentation is ≥85 bpm.

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Bar graphs showing the influence of heart rate on myocardial salvage (A), area at risk (B) and infarct size (C) in patients categorized in quintiles according to heart rate at hospital admission (details in the text).
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pone.0145495.g001: Bar graphs showing the influence of heart rate on myocardial salvage (A), area at risk (B) and infarct size (C) in patients categorized in quintiles according to heart rate at hospital admission (details in the text).

Mentions: An infarcted region on LGE images was visualized in 180 out of 187 patients, corresponded to the infarct related artery territory distribution. Mean IS among groups was 17±12% of LV mass. Not significant changes of IS over heart rate were found (13%, 16%, 21%, 19% and 16%, respectively, p = 0.075) (Table 2; Fig 1). Increased signal intensity on T2w-STIR imaging (myocardial edema) was observed in all patients. The mean size of edema among groups was 28±16% of LV mass. In all patients, the location of T2w-STIR increased signal intensity corresponded to the territory of infarct related artery distribution. The extent of myocardial edema did not change significantly as heart rate increased (29%, 29%, 32%, 28% and 23%, respectively, p = 0.217). (Table 2; Fig 1). Also the presence of microvascular obstruction was similar between groups. Conversely, the MSI significantly reduced as heart rate increased (0.54, 0.46, 0.38, 0.34 and 0.32 respectively, p<0.001). In particular, a marked improvement in salvaged myocardium was observed as heart rate was ≤ 55 bpm (group I vs. III, p = 0.017; group I vs. IV, p = 0.001; group I vs. V, p<0.001), whereas a trend toward a larger amount of salvaged myocardium was observed between group II vs. V (p = 0.101), and no significant changes were observed between groups III, IV and V (Table 2; Fig 1). Dividing our study population into two groups according to HR median value, a higher MSI value was found for heart rate <70 bpm (0.49±0.23 vs 0.33±0.22; p<0.001), whereas AAR and IS showed no significant differences (30±16 vs 26±16; p = 0.124 and 16±11 vs 17±12; p = 0.333 respectively). At multivariable analysis heart rate [OR 0.95 (95%CI: 0.92–0.97) p = 0.001], peak troponin [OR 0.995 (95%CI: 0.991–0.998) p = 0.041] and the presence of MVO [OR 0.2 (95%CI: 0.075–0.537) p<0.001] were independently associated with myocardial salvage (Table 3).


Impact of Heart Rate on Myocardial Salvage in Timely Reperfused Patients with ST-Segment Elevation Myocardial Infarction: New Insights from Cardiovascular Magnetic Resonance.

Arcari L, Cimino S, De Luca L, Francone M, Galea N, Reali M, Carbone I, Iacoboni C, Agati L - PLoS ONE (2015)

Bar graphs showing the influence of heart rate on myocardial salvage (A), area at risk (B) and infarct size (C) in patients categorized in quintiles according to heart rate at hospital admission (details in the text).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4696663&req=5

pone.0145495.g001: Bar graphs showing the influence of heart rate on myocardial salvage (A), area at risk (B) and infarct size (C) in patients categorized in quintiles according to heart rate at hospital admission (details in the text).
Mentions: An infarcted region on LGE images was visualized in 180 out of 187 patients, corresponded to the infarct related artery territory distribution. Mean IS among groups was 17±12% of LV mass. Not significant changes of IS over heart rate were found (13%, 16%, 21%, 19% and 16%, respectively, p = 0.075) (Table 2; Fig 1). Increased signal intensity on T2w-STIR imaging (myocardial edema) was observed in all patients. The mean size of edema among groups was 28±16% of LV mass. In all patients, the location of T2w-STIR increased signal intensity corresponded to the territory of infarct related artery distribution. The extent of myocardial edema did not change significantly as heart rate increased (29%, 29%, 32%, 28% and 23%, respectively, p = 0.217). (Table 2; Fig 1). Also the presence of microvascular obstruction was similar between groups. Conversely, the MSI significantly reduced as heart rate increased (0.54, 0.46, 0.38, 0.34 and 0.32 respectively, p<0.001). In particular, a marked improvement in salvaged myocardium was observed as heart rate was ≤ 55 bpm (group I vs. III, p = 0.017; group I vs. IV, p = 0.001; group I vs. V, p<0.001), whereas a trend toward a larger amount of salvaged myocardium was observed between group II vs. V (p = 0.101), and no significant changes were observed between groups III, IV and V (Table 2; Fig 1). Dividing our study population into two groups according to HR median value, a higher MSI value was found for heart rate <70 bpm (0.49±0.23 vs 0.33±0.22; p<0.001), whereas AAR and IS showed no significant differences (30±16 vs 26±16; p = 0.124 and 16±11 vs 17±12; p = 0.333 respectively). At multivariable analysis heart rate [OR 0.95 (95%CI: 0.92–0.97) p = 0.001], peak troponin [OR 0.995 (95%CI: 0.991–0.998) p = 0.041] and the presence of MVO [OR 0.2 (95%CI: 0.075–0.537) p<0.001] were independently associated with myocardial salvage (Table 3).

Bottom Line: MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001).High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium.In particular, salvaged myocardium significantly reduced when heart rate at presentation is ≥85 bpm.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Sapienza University of Rome, Rome, Italy.

ABSTRACT

Background: Previous studies evaluating the progression of the necrotic wave in relation to heart rate were carried out only in animal models of ST-elevated myocardial infarction (STEMI). Aim of the study was to investigate changes of myocardial salvage in relation to different heart rates at hospital admission in timely reperfused patients with STEMI by using cardiovascular magnetic resonance (CMR).

Methods: One hundred-eighty-seven patients with STEMI successfully and timely treated with primary coronary angioplasty underwent CMR five days after hospital admission. According to the heart rate at presentation, patients were subcategorized into 5 quintiles: <55 bpm (group I, n = 44), 55-64 bpm (group II, n = 35), 65-74 bpm (group III, n = 35), 75-84 bpm (group IV, n = 37), ≥85 bpm (group V, n = 36). Area at risk, infarct size, microvascular obstruction (MVO) and myocardium salvaged index (MSI) were assessed by CMR using standard sequences.

Results: Lower heart rates at presentation were associated with a bigger amount of myocardial salvage after reperfusion. MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001). Stepwise multivariable analysis showed heart rate, peak troponin and the presence of MVO were independent predictor of myocardial salvage. No changes related to heart rate were observed in relation to area at risk and infarct size.

Conclusions: High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium. In particular, salvaged myocardium significantly reduced when heart rate at presentation is ≥85 bpm.

Show MeSH
Related in: MedlinePlus