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 Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 32  |  Issue : 1  |  Page : 160-166

Impact of percutaneous coronary intervention on regional myocardial function in patients with chronic stable angina


1 Department of Cardiology, Faculty of Medicine, Menoufia University, Shebeen El-Kom, Egypt
2 Department of Cardiology, Cardiology at Ministry of Health, Zagazig, Sharkia, Egypt

Date of Submission17-May-2017
Date of Acceptance13-Aug-2017
Date of Web Publication17-Apr-2019

Correspondence Address:
Abdulaziz A Shaheen
Mansour Al-Barbary Street, Sand Past, Zifta, Gharbia 31641
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/mmj.mmj_336_17

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  Abstract 


Objective
To determine the impact of percutaneous coronary intervention (PCI) on regional myocardial function by tissue Doppler echocardiography (TDE) in patients with chronic stable angina and normal baseline ejection fraction.
Background
The impairment of left ventricular longitudinal function may precede the circumferential dysfunction in patients with ischemia and this impairment cannot be detected by conventional echocardiography. Successful PCI may improve this impairment and this can be detected using TDE.
Patients and methods
Between October 2013 and August 2015, this follow-up study in our teaching hospital included 25 consecutive patients with chronic stable angina and normal baseline ejection fraction who underwent PCI and were studied by TDE before, and 1 day and 6 weeks after PCI. Myocardial tissue peak velocities (E', A' and S') were recorded at the septal, lateral, anterior, and inferior angles of the mitral annulus and at the lateral tricuspid annulus.
Results
There was a highly significant improvement in E', A' and S' velocities of the mitral valve 1 day and 6 weeks after PCI at all sites: septal, lateral, anterior, and inferior (P > 0.001). Also, there was a highly significant improvement in the E' and A' velocities of the tricuspid valve 1 day and 6 weeks after PCI (P > 0.001). The S' velocity of the tricuspid valve showed a significant improvement on the first day after PCI (P = 0.02), which increased 6 weeks' after PCI to become highly significant (P > 0.001).
Conclusion
TDE parameters of diastolic and systolic functions improve early after successful PCI, and this effect persists up to 6 weeks after PCI.

Keywords: chronic stable angina, percutaneous coronary intervention, tissue Doppler echocardiography


How to cite this article:
Mousa WF, Elkersh AM, Shaheen AA. Impact of percutaneous coronary intervention on regional myocardial function in patients with chronic stable angina. Menoufia Med J 2019;32:160-6

How to cite this URL:
Mousa WF, Elkersh AM, Shaheen AA. Impact of percutaneous coronary intervention on regional myocardial function in patients with chronic stable angina. Menoufia Med J [serial online] 2019 [cited 2019 May 27];32:160-6. Available from: http://www.mmj.eg.net/text.asp?2019/32/1/160/256104




  Introduction Top


Reperfusion with apercutaneous coronary intervention (PCI) is an established procedure for the treatment of coronary artery disease (CAD) and its usefulness in symptom relief is well established [1]. PCI plays a limited role in systolic and diastolic functions in patients with chronic stable angina and preserved baseline left ventricular (LV) systolic function, and this role is unknown [2]. It has been reported that the impairment of the longitudinal function of the LV may precede circumferential ventricular dysfunction in patients with CAD [3] and this impairment in systolic and diastolic functions may be present in patients with chronic stable angina and preserved baseline LV systolic function, but the conventional two-dimensional (2D) echocardiography cannot detect this. In these patients, PCI would have the potential to improve ventricular systolic and diastolic functions after successful angioplasty [4].

Recently, tissue Doppler echocardiography (TDE) has emerged as a sensitive and quantitative measure of both systolic and diastolic longitudinal myocardial functions [5].

The aim of our study is to determine the impact of PCI on regional myocardial function by TDE in patients with chronic stable angina and normal baseline ejection fraction (EF).


  Patients and Methods Top


After approval of the study proposal by the Menoufia Ethics Committee, this follow-up study was carried out between October 2013 and August 2015 in our Cardiology Department and Catheterization Unit, Al-Ahrar Teaching Hospital; we included 25 consecutive patients with chronic stable angina and normal baseline LV systolic function, who were on standard anti-ischemic medications according to The Guidelines of the European Society of Cardiology [6]. The patients were selected from among those admitted for coronary intervention if they fulfilled the inclusion criteria after obtaining the necessary consent and explaining the procedures.

Different parameters were compared in the same sample of patients before as well as 1 day and 6 weeks after the intervention; the percentage of change in different variables was compared in different areas of the myocardium after relating it to the vessels.

Patients were excluded if they had regional wall motion abnormalities, reduced EF, abnormal LVIDd and LVIDs – Left ventricular internal diameter end diastole and end systole, Poor Echo window, previous myocardial infarction (MI), atrial fibrillation, paced rhythm, atrioventricular block, valvular heart disease, and restrictive, hypertrophic, or dilated cardiomyopathies.

All patients were subjected to a complete assessment of history with a special focus on a history of CAD, risk factors including age, hypertension, diabetes mellitus, smoking, a family history of CAD, chest pain, and angina class. Also, a thorough physical examination was performed for all patients as well as investigations such as lipid profile, 12-lead ECG, Serum creatinine, plain chest radiography, and conventional echocardiographic evaluation.

The echocardiographic equipment that we used was Hewlett Packard, SONOS 5500 (Hewlett Packard, Palo Alto, California, USA) and Toshiba model USQ1, 770a, sub symbol/xa, (Toshiba, Shibaura 1-chome, Minato-ku, Tokyo 105-8001, Japan), both equipped with TDE technology.

M-mode, 2D, and Doppler echocardiographic assessment was performed for all patients utilizing the left parasternal long axis, short axis, apical four-chamber, apical five-chamber, and apical two-chamber views. Recordings and calculations of different parameters were performed according to the recommendations of the American Society of Echocardiography [7]. TDE of both systolic and diastolic functions was performed before as well as 1 day and 6 weeks after PCI. Three major velocities were recorded (cm/s) at the annular sites of the mitral valve (MV) and tricuspid valve (TV), the peak major positive systolic velocity S' when the annulus moved toward the apex, and two major negative velocities when the annulus moved back toward the base (one during the early phase of diastole E' and another during the late phase of diastole A') [7]. They were measured with the sample volume positioned at the septal, lateral, anterior, and inferior angles of the MV annulus and on the lateral angle of the TV annulus.

  1. Peak systolic (S') velocities (normal MV = 10.8 ± 1.4) (normal TV = 15.2 ± 1.9)
  2. Early diastolic (E') velocities (normal MV = 17.7 ± 2.4) (normal TV = 15.7 ± 3.4)
  3. Late diastolic (A') velocities (normal MV = 10.4 ± 2.3) (normal TV = 15.2 ± 3.4) [8].


Coronary angiography was performed using the retrograde percutaneous transfemoral technique (Seldinger technique) and the patients were grouped according to the affected vessel, either single-vessel, two-vessel, or multivessel, and site of the lesion: either proximal, mid, or distal. Significant lesion was defined as any stenosis of at least 70% in at least one major epicardial coronary artery. The intervention performed as well as the choice of whether or not to use coronary stents were the treating cardiologists' decisions.

Patients were evaluated clinically over a 6-week follow-up period for in-hospital acute and subacute thrombosis, in-hospital bleeding, or major adverse cardiac events such as sudden death, acute MI, repeated revascularization, and heart failure.

Statistical analysis

The data were analyzed statistically using an IBM personal computer with the statistical package of the social science (SPSS), version 20 (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.). The quantitative data were presented in the form of mean ± SD, and range and qualitative data were presented in the form of numbers and percentages. The test of significance used included a paired Student's t-test. A P value of less than 0.05 was considered significant.


  Results Top


The study group included 25 patients with chronic stable angina and normal baseline EF who underwent elective PCI; 13 (52%) were men and 12 (48%) were women, and their ages ranged from 49 to 69 years, with a mean ± SD age of 57.2 ± 6.49 years.

In terms of risk factors, 14 (56%) patients were diabetic, 16 (64%) were hypertensive, 12 (48%) were dyslipidemic, two (8%) had a positive family history of CAD, and six (24%) were smokers.

In terms of anginal class, two (8%) patients had class II angina, eight (32%) had class III angina, and 15 (60%) had class IV angina according to the Canadian Cardiovascular Society grading of angina pectoris.

Coronary angiography characteristics of the study group

The coronary angiography of the study group showed that single-vessel disease was present in 21 patients [left anterior descending (LAD) coronary artery in 15 (60%), left circumflex coronary artery in two (8%), and right coronary artery (RCA) in four (16%)] and two-vessel disease was present in four patients.

The mean ± SD Gensini score was 21.7 ± 12.85, the mean number of significantly stenosed vessels per patient was 1.2 ± 0.37, and the mean number of implanted stents per patient was 1.2 ± 0.37.

Conventional echocardiography results of the study

Two-dimensional and M-mode parameters

There was no statistically significant difference in 2D and M-mode Parameters in terms of LVIDd, LVIDs, EF, fractional shortening, interventricular septum thickness in diastole, and LV posterior wall thickness in diastole at baseline, and 1 day and 6 weeks after PCI irrespective of the area supplied by the affected vessels.

Pulsed wave Doppler across the tricuspid valve and mitral valve

There was no statistically significant difference between pulsed wave Doppler measurements (E wave, A wave, and E/A ratio) across the TV and MV at baseline, and 1 day and 6 weeks after PCI irrespective of the area supplied by the affected vessels.

The trans-tricuspid mean E wave velocity was (42.0 ± 3.47 vs. 40.8 ± 4.23 vs. 43.2 ± 4.41 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.191 and P2 = 0.168), the mean A wave velocity was (116.6 ± 13.4 vs. 116.9 ± 12.2 vs. 118.1 ± 13.1 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.690 and P2 = 0.132), and the mean E/A ratio was (0.36 ± 0.09 vs. 0.35 ± 0.07 vs. 0.37 ± 0.08 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.134 and P2 = 0.685) as shown in [Table 1].
Table 1: Wave Doppler parameters across the tricuspid and mitral valves immediately before (pre), 1 day after, and 6 weeks after percutaneous coronary intervention irrespective of the area supplied by the affected vessels

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The trans-mitral mean E wave velocity was (58.1 ± 3.78 vs. 58.3 ± 2.66 vs. 59.4 ± 3.46 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.758 and P2 = 0.062), the mean A wave velocity was (67.1 ± 6.52 vs. 66.3 ± 6.23 vs. 67.3 ± 5.56 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.431 and P2 = 0.716), and the mean E/A ratio was (0.87 ± 0.04 vs. 0.88 ± 0.06 vs. 0.88 ± 0.06 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.156 and P2 = 0.068) as shown in [Table 1].

Tissue Doppler echocardiography results of the study

Tissue Doppler across the tricuspid valve

There was a statistically highly significant improvement in tissue Doppler measures of early (E') and late diastolic (A') velocities across the TV both at 1 day and 6 weeks after PCI compared with the baseline values, where the mean E' wave velocity was (12.4 ± 1.18 vs. 13.3 ± 1.10 vs. 14.5 ± 1.49 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 > 0.001 and P2 > 0.001) and the mean A' wave velocity was (15.7 ± 1.49 vs. 16.7 ± 1.74 vs. 17.7 ± 2.13 cm/s at baseline, 1 day, and 6 weeks after intervention, respectively; P1 > 0.001 and P2 > 0.001). In terms of systolic function (S'), first, there was a significant improvement on the first day after PCI (P = 0.02), which increased more after 6 weeks after PCI to become highly significant (P > 0.001), meaning that the improvement was not temporary; otherwise, it would have increased with time as the mean S' velocity was (10.9 ± 1.30 vs. 11.4 ± 0.90 vs. 12.2 ± 1.23 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 = 0.020 and P2 > 0.001) as shown in [Table 2].
Table 2: Tissue Doppler parameters across the tricuspid valve immediately before (pre), 1 day after, and 6 weeks after percutaneous coronary intervention irrespective of the area supplied by the stenosed vessel

Click here to view


This improvement in right ventricular systolic and diastolic functions was found in patients with or without an RCA intervention, indicating that there are close structural and functional relations between different areas of the myocardium.

Tissue Doppler across the mitral valve

Tissue Doppler parameters across the MV showed that there was a statistically highly significant improvement (P > 0.001) in all tissue Doppler measures for both systolic (S') and diastolic (E' and A') functions across all the angles of the MV annulus (septal, lateral, anterior, and inferior) at 1 day and 6 weeks after PCI compared with baseline values even in areas supplied with nonstenosed arteries, indicating that there are close structural and functional relations between different areas of the myocardium.

The mean septal E' wave velocity was (8.31 ± 2.45 vs. 10.2 ± 1.71 vs. 11.7 ± 2.45 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 > 0.001 and P2 > 0.001), the mean septal A' wave velocity was (10.1 ± 2.04 vs. 11.7 ± 1.90 vs. 12.8 ± 1.88 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 > 0.001 and P2 > 0.001), and the mean septal S' velocity was (7.79 ± 1.46 vs. 8.73 ± 1.39 vs. 9.91 ± 1.33 cm/s at baseline, 1 day, and 6 weeks after the intervention, respectively; P1 > 0.001 and P2 > 0.001). Also, the lateral, anterior and inferior angles of the mitral annulus showed similar improvements, with P1 and P2 value less than 0.001 in each, as shown in [Table 3] and [Figure 1].
Table 3: Tissue Doppler parameters across different angles of the mitral valve annulus immediately before (pre), 1 day after, and 6 weeks after percutaneous coronary intervention irrespective of the area supplied by the stenosed vessels

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Figure 1: Pulsed tissue Doppler across the mitral valve: Before, 1 day after, and 6 weeks after PCI. PCI, percutaneous coronary intervention.

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Improvement in the tissue Doppler parameters in relation to the target vessel revascularized

To assess whether improvement in myocardial diastolic and systolic functions was related to revascularization, patients were divided into groups according to the vessel targeted by intervention.

We found that two groups, the LAD group and the RCA group, which included sufficient numbers of patients, enabled a meaningful statistical analysis.

Tissue Doppler measures were collected from these two groups and statistical analysis showed the following:

  1. LAD group (N = 15)


  2. There was a highly significant improvement in all velocities, E', A' and S' wave velocities, at septal, lateral, anterior, and inferior angles of the mitral annulus both 1 day and 6 weeks after PCI with P value less than 0.001 as shown in [Table 4]

  3. RCA group (N = 4).


  4. There was a highly significant improvement in the E' wave velocity both 1 day and 6 weeks after PCI, with P value less than 0.001

    The A' wave velocity showed a significant improvement after 1 day, with a P value of 0.004, and a highly significant improvement 6 weeks after PCI, with P value less than 0.001

    The S' wave velocity showed a significant improvement both 1 day and 6 weeks after PCI, with P values of 0.006 and 0.004, respectively, as shown in [Table 5].
Table 4: Tissue Doppler measures in (left anterior descending group) immediately before (pre), 1 day after, and 6 weeks after percutaneous coronary intervention

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Table 5: Tissue Doppler measures in (right coronary artery group) immediately before (pre), 1 day after, and 6 weeks after percutaneous coronary intervention

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  Discussion Top


PCI is an established procedure for the treatment of coronary artery disease. Its usefulness in symptom relief is well established [1]. However, the effect of PCI on systolic and diastolic functions in patients with preserved baseline LV systolic function is unknown [2]. Recently, TDE has emerged as a sensitive and quantitative measure of both systolic and diastolic longitudinal myocardial function [5].

Pulsed tissue Doppler velocity imaging, as used in the current study, represents a robust, quick, and relatively simple method [9].

In addition, it has been reported that longitudinal LV dysfunction may precede circumferential dysfunction in patients with coronary artery disease [3].

In our study, we evaluated the applicability and usefulness of pulsed-wave (TDE) as a tool for assessment of LV and right ventricular systolic and diastolic functions in patients with coronary artery disease attributed to chronic stable angina with normal wall motion and EF by resting echocardiography undergoing elective PCI.

Different tissue Doppler imaging parameters were compared in the same sample of patients before and after the intervention by 1 day and 6 weeks; the percentage of change in different variables was compared in different areas of the myocardium after relating it to the vessels.

The main aim of this study was to detect whether there was any improvement in systolic or diastolic functions after elective PCI in patients with chronic stable angina and normal baseline EF. Also what type of both functions will show the best recovery after the intervention, and also whether this improvement, if present, will persist up to 6 weeks after the intervention.

In our study, we found no significant change in Doppler flow patterns across the MV and TV before and after the intervention; also, the improvement in systolic and diastolic functions after the intervention was detected only by pulsed wave TDE and these data were in agreement with multiple studies.

  1. Diller et al. [10] examined Doppler flow indices in a similar group of patients and found no significant difference before and after the intervention, in contrast to tissue Doppler, which could detect diastolic and systolic function improvements early after successful PCI; this effect persisted up to 6 weeks after intervention
  2. Park et al. [11] also did not observe any improvement in Doppler flow patterns in patients before and after intervention in ST-elevation MI
  3. Baykan et al. [12] in a study to assess LV systolic and diastolic function by pulsed wave TDE in patients with or without preinfarction angina in acute MI, concluded that LV diastolic function was better in patients with preinfarction angina than in patients without preinfarction angina. This condition could not be detected by conventional mitral inflow Doppler velocities, but could be detected by TDE.


This lack of agreement between parameters derived from conventional Doppler and TDE in different clinical situations could be explained by the complexity of factors affecting Doppler flow patterns including random factors such as heart rate, filling status, age, and medications as explained by Karwatowski et al. [13].

In our study, there was a global improvement in both systolic and diastolic TDE indices irrespective of the artery revascularized; the same result was reported by Balachandran et al. [14]; Hsieh et al. [15]; and Pujadas et al. [16].

It seems that the myocardial geometry at cellular and structural levels make the myocardium act as a single unit, showing improvements in remote areas to some extent even if the opened artery was not supplying that area directly.

When we used certain statistical methods to rank the improvement in local TDE according to the vessels revascularized, we found an excellent agreement with the LV assignments to coronary territory on the basis of data from the 2005 consensus statement by the American Society for Echocardiography and the European Association for Echocardiography [17].

This reflects the accuracy and reproducibility of TDE measurements, and shows that the improvement in regional functions is the most in areas supplied directly by the vessel revascularized.

Limitations

In this study, we used TDE. Other measurement technologies might have yielded different results, but tissue Doppler is a universally accepted method of quantifying longitudinal and circumferential myocardial behavior and is used widely in clinical practice. In addition, we did not measure inducible ischemia on stress testing before or after PCI. Further studies, potentially in combination with myocardial viability analysis, are desirable to assess which modality is superior in detecting improved myocardial function and how this relates to improved myocardial perfusion.

Furthermore, the relatively small sample size of the current study precluded evaluation of the impact of individual coronary artery revascularization on regional Doppler indices.


  Conclusion Top


The effect of PCI in patients with chronic stable angina goes beyond pain relief as it rejuvenates the apparently normal myocardium at the level of both systolic and diastolic functions.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
  References Top

1.
Smith SC Jr, Feldman TE, Hirschfeld JW, Jacobs AK, Kern MJ, King SB 3rd, et al. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention – Summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update the 2001 Guidelines for Percutaneous Coronary Intervention). J Am Coll Cardiol 2006; 47:216–235.  Back to cited text no. 1
    
2.
Wang M, Yip G, Yu CM, Zhang Q, Zhang Y, Tse D, et al. Independent and incremental prognostic value of early mitral annulus velocity in patients with impaired left ventricular systolic function. J Am Coll Cardiol 2005; 45:272–277.  Back to cited text no. 2
    
3.
Henein MY, Priestley K, Davarashvili T, Buller N, Gibson DG. Early changes in left ventricular subendocardial function after successful coronary angioplasty. Br Heart J 1993; 69:501–506.  Back to cited text no. 3
    
4.
Sahn DJ, DeMaria A, Kisslo J, Weyman A. Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements. Circulation 1978; 58:1072–1083.  Back to cited text no. 4
    
5.
Veyrat C, Larrazet F, Cohen L, Laborde F, Pellerin D. Detection of prominent left anterior descending coronary artery stenosis for patients with stable angina using Doppler tissue echocardiography. J Am Soc Echocardiogr 2005; 18:821–829.  Back to cited text no. 5
    
6.
Fox K, Garcia MA, Ardissino D, Buszman P, Camici PG, Crea F, et al. Guidelines on the management of stable angina pectoris: executive summary: The Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology. Eur Heart J 2006; 27:1341–1381.  Back to cited text no. 6
    
7.
Alam M, Wardell J, Andersson E, Samad BA, Nordlander R. Characteristics of mitral and tricuspid annular velocities determined by pulsed wave Doppler tissue imaging in healthy subjects. J Am Soc Echocardiogr 1999; 12:618–628.  Back to cited text no. 7
    
8.
Dalen H, Thorstensen A, Vatten LJ, Aase SA, Stoylen A. Reference values and distribution of conventional echocardiographic doppler measures and longitudinal tissue Doppler velocities in a population free from cardiovascular disease. Circ Cardiovasc Imaging 2010; 3:614–622.  Back to cited text no. 8
    
9.
Smiseth OA, Stoylen A, Ihlen H. Tissue Doppler imaging for the diagnosis of coronary artery disease. Curr Opin Cardiol 2004; 19:421–429.  Back to cited text no. 9
    
10.
Diller GP, Wasan BS, Thom SA, Foale RA, Hughes AD, Francis DP, et al. Evidence of improved regional myocardial function in patients with chronic stable angina and apparent normal ventricular function – A tissue Doppler study before and after percutaneous coronary intervention. J Am Soc Echocardiogr 2009; 22:177–182.  Back to cited text no. 10
    
11.
Park SM, Miyazaki C, Prasad A, Bruce CJ, Chandrasekaran K, Rihal C, et al. Feasibility of prediction of myocardial viability with Doppler tissue imaging following percutaneous coronary intervention for ST elevation anterior myocardial infarction. J Am Soc Echocardiogr 2009; 22:183–189.  Back to cited text no. 11
    
12.
Baykan M, Yilmaz R, Celik S, Orem C, Kaplan S, Erdol C. Assessment of left ventricular systolic and diastolic function by Doppler tissue imaging in patients with preinfarction angina. J Am Soc Echocardiogr 2003t; 16:1024–1030.  Back to cited text no. 12
    
13.
Karwatowski SP, Brecker SJ, Yang GZ, Firmin DN, Sutton MS, Underwood SR. Mitral valve flow measured with cine MR velocity mapping in patients with ischemic heart disease: comparison with Doppler echocardiography. J Magn Reson Imaging 1995; 5:89–92.  Back to cited text no. 13
    
14.
Balachandran KP, Berry C, Pell AC, Vance BD, Oldroyd KG. Improvement in left ventricular function following successful rescue percutaneous coronary intervention is independent of time-to-reperfusion. J Invasive Cardiol 2006;18:330–333.  Back to cited text no. 14
    
15.
Hsieh IC, Huang HL, See LC, Chang SH, Chang HJ, Hung KC, et al. Improvement in left ventricular function following coronary stenting in patients with acute myocardial infarction: 6-month and 3-year follow-up. Int J Cardiol 2006; 111:209–216.  Back to cited text no. 15
    
16.
Pujadas S, Martin V, Rosselló X, Carreras F, Barros A, Leta R, et al. Improvement of myocardial function and perfusion after successful percutaneous revascularization in patients with chronic total coronary occlusion. Int J Cardiol. 2013; 169:147–152.  Back to cited text no. 16
    
17.
Lang RM, Bierig M, Devereux RB, Flachskampf FA, Foster E, Pellikka PA, et al. Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification xWriting Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology. J Am Soc Echocardiogr 2005; 18:1440–1463.  Back to cited text no. 17
    


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