https://rpubs.com/alex_istrate/

1 INDRODUCTION

Myocardial deformation imaging using two-dimensional speckle-tracking echocardiography (STE) has become a very useful technique for the assessment of left ventricular (LV) function after acute myocardial infarction (AMI). However, it has been showed that changes in afterload could alter strain calculation, leading to misinterpretation of the results.

Myocardial work (MW) is a new parameter that integrates both strain and afterload, through dynamic non-invasive LV pressure measurements. MW has showed superiority compared to LV global longitudinal strain (GLS) for coronary artery disease prediction, but is not yet validated as a prognostic parameter for long-term risk assessment after AMI.

2 PURPOSE

The aim of this study is to see whether MW could stand as a prognostic marker for patients with coronary artery disease and if it is superior to GLS for short- and long-term risk assessment.

3 METHODS

Forty-five patients with ST-elevation and non-ST-elevation MI, regardless of interested territory, admitted in our Cardiology Department between 1st and 31st of August were included. Patients with history of coronary artery disease, heart failure with reduced ejection fraction or severe hypertension were not included. We evaluated GLS and global MW index (GWI) 3-5 days after percutaneous revascularization. GWI was calculated as the product of strain x systolic blood pressure. Patients were divided in two groups: Group 1 – patients that presented rehospitalization for cardiac decompensation, including new coronary event or heart failure symptoms and Group 2 – patients without rehospitalization, at 4-month follow-up. We then compared GLS and GWI between the two groups and the relation between GLS and GWI in group 1.

4 RESULTS

------------------------------------------------------------------------------ 
Describe baza_de_date (tbl_df, tbl, data.frame):

data frame: 45 obs. of  7 variables
        43 complete cases (95.6%)

  Nr  ColName            Class    NAs       Levels         Label             
  1   Diagnosis          factor   .         (2): 1-STEMI,  Diagnosis         
                                            2-NSTEMI                         
  2   Age (years)        numeric  .                        Age (years)       
  3   Sex                factor   .         (2): 1-F, 2-M  Sex               
  4   Culprit vessel     factor   2 (4.4%)  (3): 1-LAD,    Culprit vessel    
                                            2-RCA, 3-LCX                     
  5   GLS-2d             numeric  .                        GLS-2d            
  6   GWI                numeric  .                        Global            
                                                           myocardial        
                                                           work index        
  7   Rehospitalization  factor   .         (2): 1-yes,    Rehospitalizati...
                                            2-no                             


------------------------------------------------------------------------------ 
1 - Diagnosis (factor - dichotomous) :
  Diagnosis


  length      n    NAs unique
      45     45      0      2
         100.0%   0.0%       

        freq   perc  lci.95  uci.95'
STEMI     31  68.9%   54.3%   80.5%
NSTEMI    14  31.1%   19.5%   45.7%

' 95%-CI Wilson

------------------------------------------------------------------------------ 
2 - Age (years) (numeric) :
  Age (years)


  length       n    NAs  unique     0s   mean  meanCI
      45      45      0      31      0  64.29   59.99
          100.0%   0.0%           0.0%          68.59
                                                     
     .05     .10    .25  median    .75    .90     .95
   43.20   46.00  54.00   64.00  78.00  83.20   84.80
                                                     
   range      sd  vcoef     mad    IQR   skew    kurt
   58.00   14.32   0.22   16.31  24.00  -0.01   -1.01
                                                     
lowest : 35.0, 40.0, 43.0, 44.0, 46.0 (3)
highest: 82.0, 84.0 (2), 85.0, 86.0, 93.0

------------------------------------------------------------------------------ 
3 - Sex (factor - dichotomous) :
  Sex


  length      n    NAs unique
      45     45      0      2
         100.0%   0.0%       

   freq   perc  lci.95  uci.95'
F    18  40.0%   27.0%   54.5%
M    27  60.0%   45.5%   73.0%

' 95%-CI Wilson

------------------------------------------------------------------------------ 
4 - Culprit vessel (factor) :
  Culprit vessel


  length      n    NAs unique levels  dupes
      45     43      2      3      3      y
          95.6%   4.4%                     

   level  freq   perc  cumfreq  cumperc
1    LAD    17  39.5%       17    39.5%
2    RCA    17  39.5%       34    79.1%
3    LCX     9  20.9%       43   100.0%

------------------------------------------------------------------------------ 
5 - GLS-2d (numeric) :
  GLS-2d


  length       n     NAs  unique     0s    mean  meanCI
      45      45       0      36      0  -11.31  -12.21
          100.0%    0.0%           0.0%          -10.41
                                                       
     .05     .10     .25  median    .75     .90     .95
  -16.00  -15.44  -13.60  -11.00  -9.40   -7.88   -7.12
                                                       
   range      sd   vcoef     mad    IQR    skew    kurt
   11.90    3.00   -0.26    3.11   4.20    0.07   -0.79
                                                       
lowest : -16.80, -16.10, -16.0 (2), -15.60, -15.20
highest: -7.80, -7.60, -7.0, -5.0, -4.90

------------------------------------------------------------------------------ 
6 - GWI (numeric) :
  Global myocardial work index

    length       n     NAs    unique        0s      mean    meanCI
        45      45       0        44         0  1'099.04  1'005.32
            100.0%    0.0%                0.0%            1'192.77
                                                                  
       .05     .10     .25    median       .75       .90       .95
    693.40  807.40  925.00  1'036.00  1'182.00  1'560.80  1'617.00
                                                                  
     range      sd   vcoef       mad       IQR      skew      kurt
  1'501.00  311.96    0.28    210.53    257.00      0.59      0.15
                                                                  
lowest : 401.0, 628.0, 686.0, 723.0, 807.0
highest: 1'612.0, 1'613.0, 1'618.0, 1'824.0, 1'902.0

------------------------------------------------------------------------------ 
7 - Rehospitalization (factor - dichotomous) :
  Rehospitalization


  length      n    NAs unique
      45     45      0      2
         100.0%   0.0%       

     freq   perc  lci.95  uci.95'
yes     8  17.8%    9.3%   31.3%
no     37  82.2%   68.7%   90.7%

' 95%-CI Wilson

Table 1: All parameters of the sample.

Variable

Details

Total

N=

45

Diagnosis

STEMI

31 (68.9%)

NSTEMI

14 (31.1%)

Age (years)

M (min:max)

64 (35:93)

μ ±SD

64.29 ±14.3

Sex

F

18 (40.0%)

M

27 (60.0%)

Culprit vessel

LAD

17 (39.5%)

RCA

17 (39.5%)

LCX

9 (20.9%)

GLS-2d

M (min:max)

-11 (-16.8:-4.9)

μ ±SD

-11.31 ±3.0

Global myocardial work index

M (min:max)

1036 (401:1902)

μ ±SD

1099.04 ±312.0

Rehospitalization

8 (17.8%)

μ ±SD = Mean (standard deviation); M (min:max) = Median (min:max);

Figure  1: Age distribution, at admission, colored by sex. (| mean, ¦ median).

Figure 1: Age distribution, at admission, colored by sex. (| mean, ¦ median).

Figure  2: Sex and Rehospitalization.

Figure 2: Sex and Rehospitalization.

Figure  3: Diagnosis and Culprit vessel.

Figure 3: Diagnosis and Culprit vessel.

Table 2: Parameters of the sample by Rehospitalization.

Variable

Details

yes

no

Total

Statistics

Rehospitalization

8 (17.8%)

37 (82.2%)

45

Diagnosis

STEMI

5 (62.5%)

26 (70.3%)

31 (68.9%)

OR=0.71 [0.14, 3.48] (p=0.689)

NSTEMI

3 (37.5%)

11 (29.7%)

14 (31.1%)

Age (years)

M (min:max)

64.5 (35:93)

64 (40:86)

64 (35:93)

T-test: p=0.972

μ ±SD

64.12 ±18.0

64.32 ±13.7

64.29 ±14.3

Sex

F

2 (25.0%)

16 (43.2%)

18 (40.0%)

OR=0.44 [0.08, 2.46] (p=0.445)

M

6 (75.0%)

21 (56.8%)

27 (60.0%)

Culprit vessel

LAD

4 (50.0%)

13 (37.1%)

17 (39.5%)

V=0.12 (p=0.735)

RCA

3 (37.5%)

14 (40.0%)

17 (39.5%)

LCX

1 (12.5%)

8 (22.9%)

9 (20.9%)

GLS-2d

M (min:max)

-10.3 (-13:-5)

-11.4 (-16.8:-4.9)

-11 (-16.8:-4.9)

T-test: p=0.252

μ ±SD

-10.20 ±2.75

-11.55 ±3.03

-11.31 ±3.0

Global myocardial work index

M (min:max)

841 (401:1028)

1117 (628:1902)

1036 (401:1902)

T-test: p=0.002

μ ±SD

801.25 ±198.8

1163.43 ±295.5

1099.04 ±312.0

OR = odds-ratio [95% CI] and p value from Fisher test);

4.1 GLS-2d & GWI

Figure  4: GLS-2d and GWI distributions. (| mean, ¦ median).

Figure 4: GLS-2d and GWI distributions. (| mean, ¦ median).

Figure  5:  (◆ mean, — median).

Figure 5: (◆ mean, — median).

5 CONCLUSIONS

6 References

  1. R Core Team (2019). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/.