Usefulness of non-invasive myocardial work to predict left ventricular recovery and acute complications after acute anterior myocardial infarction treated by primary angioplasty

Background

Predicting left ventricular (LV) recovery after acute ST-elevation myocardial infarction (STEMI) is challenging and of prognostic importance.

Objective

To evaluate the usefulness of non-invasive myocardial work (MW), a new index of global and regional myocardial performance, to predict LV recovery and in-hospital complications after STEMI.

Methods

Ninety-three consecutive patients with anterior STEMI (mean age, 59±12 years) treated by primary angioplasty underwent transthoracic echocardiography (TTE) within 24–48 hours after angioplasty and a median of 92 days at follow-up. MW is derived from the non-invasive strain-pressure loop obtained from the 2D strain data, integrating in its calculation the non-invasive brachial arterial pressure. Segmental LV recovery was defined as a normalization of segmental wall motion abnormalities of the affected segments and global recovery as an absolute improvement of left ventricular ejection fraction (LVEF) greater than 5% in patients with baseline LVEF <50%. In-hospital complications were defined as a composite of death, reinfarction, heart failure, and LV apical thrombus.

Results

1642 segments were studied and MW was impaired in infarct segments, more severely in no recovery versus recovery segments (MW index, constructive MW, MW efficiency, all, p<0.01). Furthermore, global MW was significantly correlated to acute and follow-up LVEF and global longitudinal strain (GLS) (all, p<0.01). Constructive MW was the best indice to predict segmental (p<0.01 versus MW index, MW efficiency, and wasted work), and global recovery (p<0.05 versus GLS) with an independent association (all, p<0.01). Moreover, global constructive MW was independently associated to in-hospital complications which occurred in 18 patients (p<0.01).

Conclusion

In patients with anterior STEMI treated by primary angioplasty, acute constructive MW is an independent predictor of segmental and global LV recovery, as well as in-hospital complications.

Funding Acknowledgement

Type of funding source: None

The left atrial function is transiently impaired in Tako-tsubo cardiomyopathy and associated to in-hospital complications: a prospective study using two-dimensional strain

Tako-tsubo cardiomyopathy (TTC) is characterized by the presence of transient left ventricular (LV) dysfunction. Whether left atrial (LA) function is also impaired in this setting is unclear. To assess prospectively LA peak systolic longitudinal strain (LAS) by two-dimensional strain at the acute phase of TTC and after recovery and its association with in-hospital complications. 40 patients with typical TTC (mean age 79.5 ± 10 years) underwent transthoracic-Doppler echocardiography at the acute phase and at follow-up (32 ± 18 days later), including the measurement of the LAS (mean of maximal strain from the 4-2 chamber views). A control group of 15 patients (75 ± 7 years, 13 women) without overt cardiovascular disease served as a comparative group. In-hospital complication was a composite of death, heart failure, cardiogenic shock, LV thrombus, and sustained ventricular arrhythmia. In the TTC group, LAS improved significantly between the two examinations from 15 ± 5.5% to 27 ± 8% (p < 0.01) whereas LA volume did not change (p = NS). In the control group LAS was 30 ± 4% (p < 0.01 vs. TTC acute phase, p = NS vs. TTC follow-up). In TTC, at the acute phase LAS was independently correlated to LV global longitudinal strain (LVGLS), and after recovery to E/e', and the change of LAS was independently correlated to the change of the LVGLS (all, p < 0.01). Furthermore LAS was independently correlated to in-hospital complications (p < 0.01). LA function (reservoir) is transiently impaired in TTC and associated to in-hospital complications. Furthermore, the improvement of LAS parallel the dynamic improvement of LVGLS suggests that TTC induces a transient global left heart dysfunction.

Apical rotation, a simplified index of left ventricular twist is independently linked to recovery after acute anterior myocardial infarction

BACKGROUND

It is unclear whether apical rotation (Ar), which in normal setting represents the dominant contributions to LV twist by comparison to basal rotation (Br), predicts viability in acute anterior myocardial infarction (AMI). Our objective was to test the usefulness of Ar as a simple index to predict LV recovery after AMI.

METHODS

Fourty-five consecutive patients (mean age 60±14 years, mean LVEF 44±7%) with first AMI treated successfully by primary angioplasty underwent prospectively a comprehensive transthoracic-Doppler echocardiography including analysis of Ar, Br, and LV twist by 2-dimensional speckle tracking, using a basal and apical short axis-views, within 24h after angioplasty and 3-6months later. Recovery was defined as: - the normalization of the wall motion of more than 50% of initial abnormal segments (R1) and; - absolute improvement of LVEF≥10% (R2).

RESULTS

A better correlation was found between Ar and LV twist at each stage of the disease than between Br and LV twist (acute phase, R=0.77 vs. R=0.35; follow-up, R=0.9 vs. R=0.3 [all, P<0.001 for Ar, and all, P≤0.05 for Br]). Furthermore, a better correlation was found between Ar and follow-up LVEF (R=0.57), wall motion score index (R=0.44), and global longitudinal strain (R=0.54) (all, P<0.001) than between LV twist and the same parameters (R=0.39; R=0.32; R=0.32 respectively, all P<0.05). (For Br, all, P=NS). Ar as well as LV twist were significantly associated with recovery (all, P<0.01) with an area under the curve (AUC) higher for the former than for the latter (R1, N=18: AUC-Ar=0.81 and AUC-LV twist=0.69, P=0.05; R2, N=19: AUC-Ar=0.82, AUC-LV twist=0.75, P=0.1). In multivariate analysis, Ar remained an independent predictor of recovery R1 and R2 instead of LV twist (all, P≤0.01). Using a ROC curve analysis, the best cut-off of Ar to predict recovery R2 was 6.5°, with Se=77% Sp=85%, P<0.001.

CONCLUSION

Apical rotation is an independent predictor of segmental and global LV recovery after anterior acute anterior myocardial infarction treated successfully by primary angioplasty.

Assessment of left anterior descending artery stenosis of intermediate severity by fractional flow reserve, instantaneous wave-free ratio and non-invasive coronary flow reserve

Assessment of the functional significance of left anterior descending coronary artery (LAD) stenosis of intermediate severity is challenging and often based on fractional flow reserve (FFR). The instantaneous wave-free ratio (IFR), a new vasodilator-free index of coronary stenosis severity, and non-invasive coronary flow reserve (CFR) by transthoracic Doppler echocardiography are also potentially useful. A direct comparison of FFR, IFR, and non-invasive CFR has never been performed. Our objective was to test the usefulness of non-invasive CFR by comparison to invasive FFR and IFR in patients with LAD stenosis of angiographic intermediate severity and stable coronary artery disease.

METHODS

Ninety-four stable consecutive patients (mean age, 68±10years; 19 women) with angiographic proximal or mid LAD stenosis of intermediate severity (40-70% diameter stenosis on quantitative coronary angiography), were prospectively studied. They underwent IFR that was calculated as a trans-lesion pressure ratio during a specific period of baseline diastole, FFR with intracoronary bolus adenosine (180μg), and CFR using intravenous adenosine (140μg/kg/min over 2min) in the distal part of the LAD, the same day. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity and FFR as distal pressure divided by mean aortic pressure during maximal hyperemia.

RESULTS

The mean values of IFR, FFR, and CFR were 0.88±0.07, 0.81±0.09, and 2.4±0.6 respectively. A significant correlation was found between CFR and FFR (R=0.63, curvilinear relationship), FFR and IFR (R=0.6, linear relationship), and between CFR and IFR (R=0.5) (all, P<0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR≤0.8, N=31) was IFR≤0.88 with a sensitivity (Se) of 74%, specificity (Sp) of 73%, AUC 0.81±0.04; and CFR≤2 with a Se=77%, Sp=89%, AUC 0.88±0.04, (all, P<0.001). Based on these cut-offs, discordant results between CFR and FFR were observed in 14 cases (agreement 85%), between CFR and IFR in 26 cases (agreement 72%), and between IFR and FFR in 26 cases (agreement 72%).

CONCLUSION

In stable patients with LAD stenosis of intermediate severity, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation and agreement between CFR and FFR than with IFR.

Assessment of left anterior descending artery stenosis of intermediate severity by fractional flow reserve, instantaneous wave-free ratio, and non-invasive coronary flow reserve

To test the usefulness of non-invasive coronary flow reserve (CFR) by transthoracic Doppler echocardiography by comparison to invasive fractional flow reserve (FFR) and instantaneous wave-free ratio (IFR), a new vasodilator-free index of coronary stenosis severity, in patients with left anterior descending artery (LAD) stenosis of intermediate severity (IS) and stable coronary artery disease. 94 consecutive patients (mean age 68 ± 10 years) with angiographic LAD stenosis of IS (50-70 % diameter stenosis), were prospectively studied. IFR was calculated as a trans-lesion pressure ratio during the wave-free period in diastole; FFR as distal pressure divided by mean aortic pressure during maximal hyperemia (using 180 μg intracoronary adenosine); and CFR as hyperemic peak LAD flow velocity divided by baseline flow velocity using intravenous adenosine (140 μg/kg/min over 2 min). The mean values of IFR, FFR, and CFR were 0.88 ± 0.07, 0.81 ± 0.09, and 2.4 ± 0.6 respectively. A significant correlation was found between CFR and FFR (r = 0. 68), FFR and IFR (r = 0.6), and between CFR and IFR (r = 0.5) (all, p < 0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR ≤ 0.8, n = 31) was IFR ≤ 0.88 with a sensitivity (Se) of 74 %, specificity (Sp) of 73 %, AUC 0.81 ± 0.04, accuracy 72 %; and CFR ≤ 2 with a Se = 77 %, Sp = 89 %, AUC 0.88 ± 0.04, accuracy 85 % (all, p < 0.001). In stable patients with LAD stenosis of IS, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation between CFR and FFR than between CFR and IFR, and a trend to a better diagnostic performance for CFR versus IFR.

Systolic anterior motion of the mitral valve in tako-tsubo cardiomyopathy: Still a matter of debate?

We present a case which developed a typical tako-tsubo-like cardiomyopathy (TTC) during dobutamine stress echocardiography (DSE). Its originality is related to several findings, which have never been described simultaneously in the same patient. This 63-year-old woman with normal coronary angiography and no evidence of coronary vasospasm had a biphasic response to DSE, a finding which usually occurs in coronary artery disease. Moreover, the symmetric extensive wall motion abnormalities (WMA) occurred simultaneously with the development of a systolic anterior motion of the mitral valve (SAM) and left ventricular obstruction, and was clinically asymptomatic. Although in TTC the stunning usually occurs for several days, WMA and SAM resolved within few minutes after cessation of dobutamine and administration of a beta-blocker. And finally, exercise echo performed at the same target heart rate few days later did not induce neither a SAM nor WMA, which suggests that left ventricular obstruction could have played a role in the pathogenesis of this case by supply-demand mismatch. Concomitant coronary microvascular dysfunction was also demonstrated by a reduction of the non-invasive coronary flow reserve in the distal part of the left anterior descending artery.

[Incidence, associated factors, and follow-up of hospital heart failure complicating acute anterior myocardial infarction successfully treated by primary angioplasty]

Heart failure (HF) complicating acute myocardial infarction (AMI) is of poor prognosis and is often associated with patient's characteristics and success of reperfusion strategies. However, few data is available regarding the high-risk subgroup of patients with anterior AMI treated successfully by primary angioplasty. The aim of the study was to assess the incidence, associated factors, and the future of HF occurring during hospitalisation, in the setting of anterior AMI treated successfully by primary angioplasty.

METHODS

Eighty-five consecutive patients with anterior AMI treated successfully by primary angioplasty (final angiographic TIMI flow grade=3, without residual stenosis) were included. Clinical, biochemical, angiographic, and echocardiographic data were prospectively collected and compared between patients with (Killip 2 and 3) and without HF during hospitalisation.

RESULTS

Fifteen patients had HF (18%) during hospitalisation and 70 did not. By comparison to patients without HF, patients with HF were more frequently diabetics, had troponin peak and CPK, leucocytes count, and fasting glucose higher, LVEF and wall motion score index in the left anterior descending territory (WMSi-lad) poorer, and a lower non-invasive coronary flow reserve (CFR) in the LAD 24hours after angioplasty (all, P<0.05). In multivariate analysis, fasting glucose, leucocytes count after angioplasty, CFR and WMSi-lad were independently associated with HF, even after adjusting with angiographic variables (all, P<0.05). At 6months, patients with HF had less recovery of LV function and higher frequency of adverse LV remodelling (58% versus 20%, P<0.01) by comparison to patients without HF.

CONCLUSION

In conclusion, HF is not uncommon even after successful primary angioplasty for anterior AMI (nearly one patient out of 5), is associated with hyperglycaemia and inflammation, a poor microvascular reperfusion, and left ventricular systolic function, and is more frequently complicated by adverse LV remodelling and lack of LV recovery.

[Non-invasive coronary flow reserve is an independent predictor of exercise capacity after acute anterior myocardial infarction]

BACKGROUND

After acute myocardial infarction (MI) coronary microvascular impairment and reduced exercise capacity are both determinant of prognosis.

OBJECTIVE

We tested whether non-invasive coronary flow reserve (CFR) performed after MI predicts post-MI exercise capacity (EC).

METHODS

Fifty consecutive patients (pts) (mean age 56.5±11years, 30% women) with a first reperfused ST-elevation anterior MI, and sustained TIMI 3 flow after mechanical reperfusion, underwent prospectively non-invasive CFR in the distal part of the left anterior descending artery (LAD), using intravenous adenosine infusion (0.14mg/kg per minute, within 2min), within 24h after successful primary coronary angioplasty (CFR 1), and 4±1.6months later after a period of convalescence and a cardiac rehabilitation program (CFR 2). CFR was defined as peak hyperaemic LAD flow velocity divided by baseline flow velocity. All pts also underwent semi-supine exercise stress echocardiography (ESE) the same day of CFR 2. ESE was performed at an initial workload of 25-30watts with a 20watts increase at 2-minute intervals. Beta-blockers were withheld 24h before ESE.

RESULTS

The mean CFR 2 increased significantly when compared to CFR 1 (2.9±0.65 versus 1.9±0.4, P<0.01). During ESE, percentage of maximal predict heart rate achieved was 82±12%, maximal workload 95±30watts, exercise duration 486±155s, the ratio of double product 3.1±0.8, and EC 5.8±1.1 metabolic equivalents. No ischemia was induced during ESE in all pts, and the degree of mitral regurgitation did not differ significantly between rest and exercise. CFR 2 was significantly correlated to all indices related to EC (all, P<0.01), whereas CFR 1 was correlated to LV systolic function at follow-up (P<0.05) but not to EC. In multivariate analysis including age, sex, and body mass index, CFR 2 remained an independent predictor of EC (P<0.01).

CONCLUSION

Contrarily to acute CFR, CFR at follow-up is an independent predictor of EC after reperfused anterior MI. This suggests that the improvement of the coronary microcirculation is closely linked to the physical aptitude after MI.

[Assessment of left ventricular twist mechanics by two-dimensional strain in severe aortic stenosis with preserved ejection fraction]

Left ventricular (LV) twist is increased in aortic stenosis (AS) and the hypothesis of a compensatory mechanism is suggested but not established. Our aim was to assess LV twist mechanics in severe AS (<1cm(2) or 0.6cm(2)/m(2)) with preserved LV ejection fraction (LVEF>50%), and to analyze its relationship with LV systolic longitudinal function, early impaired in this setting, LV diastolic function, and symptomatic status.

METHODS

Forty-five consecutive patients with severe AS and preserved LVEF (mean age 73±11 years, 47% female, LVEF 68±11%, 67% symptomatic) underwent a transthoracic echocardiography including a bidimensional strain analysis by speckle tracking method, and were compared to a control group matched for age and sex (n=15). Global longitudinal strain (GLS) was measured using the four, two, and three apical views, and LV twist mechanics from the basal and apical short axis views. LV twist was defined as the net difference between apical and basal rotation, and LV twisting and untwisting rate (in°/s) were derived from twist curves.

RESULTS

Peak apical rotation, LV twist (25±8° vs 20±6), as well as peak systolic and diastolic apical rotation rate, and peak LV twisting rate were significantly higher in patients with AS when compared to controls (all, P<0.05), whereas, the other parameters of LV twist mechanics including basal rotation, were not significantly different between groups. By contrast, the GLS was significantly lower in patients with AS when compared to controls (-17.9±4 vs -20.5±2%, P<0.01). In addition, the GLS was significantly correlated to LV torsion (r=-0.42, P<0.01). Moreover, LV twist progressively impaired with the worsening of diastolic dysfunction and with symptoms onset.

CONCLUSION

LV twist is increased in severe AS with preserved LVEF, compensating the impairment of systolic longitudinal function. However, above a certain threshold LV twist deteriorates, attesting the failure of the compensatory mechanisms, leading to advanced diastolic dysfunction and symptom onset.

[Influence of leukocytes on coronary flow reserve, left ventricular systolic function, and in-hospital events, in patients with acute anterior myocardial infarction treated by primary angioplasty]

OBJECTIVE

To assess the relationship between leukocyte count, non invasive coronary flow reserve (CFR), left ventricular systolic function, and in-hospital adverse events in acute anterior myocardial infarction (AMI) treated by primary angioplasty.

METHODS

Leukocyte count at admission and within 24h after angioplasty, and differential count at admission were obtained in 72 consecutive patients with a first AMI (mean age 56±12 years) successfully treated by primary angioplasty. Transthoracic Doppler echocardiography was performed within 24h after angioplasty and 3 months later to assess the CFR (using intravenous adenosine), in the left anterior descending artery (LAD), left ventricular ejection fraction (LVEF) and the wall motion score index using the nine segments assigned to the LAD territory (WMSi-lad). In hospital events were defined as death, heart failure (Killip≥2) and reinfarction.

RESULTS

Leukocyte count was higher before and after angioplasty in patients with impaired acute CFR (<1.7), when compared to patients without such impairment (P≤0.01), and a significant correlation was found between CFR and leukocyte, neutrophil and monocyte count (P<0.05). Leukocyte (before and after angioplasty), and neutrophil count, were lower in patients with recovery of global and regional LV function (P<0.05). A significant correlation was found between leukocyte count before and after angioplasty, and, initial and follow-up LVEF, and WMSi-lad (all, P≤0.01). Leukocyte (before and after angioplasty) and monocyte count were higher in patients with in-hospital events (n=14), by comparison to patients without events (all, P<0.01). In multivariate analysis, leukocyte count after angioplasty was an independent predictor of CFR, and in-hospital events, and neutrophil count of WMSi-lad at follow-up (all, P<0.05).

CONCLUSION

In the first AMI treated successfully by primary angioplasty, leukocyte count is inversely correlated to CFR, and global and regional LV systolic function at follow-up. These links are higher after than before reperfusion. And, leukocyte count after angioplasty is an independent predictor of in-hospital adverse events.

[Signal averaging electrocardiography in chronic alcoholism]

Cardiovascular death is the main cause of mortality in chronic alcoholics, perhaps due to a pro-arrhythmogenic effect of alcohol associated with infraclinical myocardial lesions. The authors investigated prospectively 41 patients (average age: 49.7 years) who were chronic alcoholics but had no acute alcoholic episodes for cardiac disease (ECG, signal averaging for late ventricular potentials, echocardiography and Holter ECG monitoring) and hepatic disease (liver biopsy). The history of alcoholism was 14 +/- 9 years, the quantity of alcohol ingested before they stopped drinking being 89 +/- 31 grammes/day. Thirty per cent of patients displayed 2 or 3 criteria of late ventricular potentials (LP). The authors demonstrated a correlation between the daily quantity of alcohol consumed before stopping drinking and the duration of the filtered QRS complex (p = 0.02). Moreover, the frequency of fatty infiltration found on liver biopsy, greater in alcoholics with LP (35% versus 19%, p = 0.025) correlated with the amplitude of the last 40 ms of the average QRS (p = 0.0485), with the duration of potentials of less than 40 microvolts (p = 0.05) and, above all, with the number of criteria of LP (p = 0.02). Finally, the presence of LP was also related to the following biological abnormalities: GGT (p = 0.027), ASAT (p = 0.046), ALAT (p = 0.039). The ECG abnormalities may reflect early infra-clinical myocardial lesions secondary to cellular metabolic abnormalities perhaps analogous to the fatty hepatic changes. However, the prognostic value of these signal-averaging ECG abnormalities remains unknown.