cardiovascular ( cv ) diseases are the leading cause of mortality in hemodialysis ( hd ) patients , accounting for nearly half of all deaths in this patient population .
the cv mortality rate of hd patients is higher by a factor of ~10 than that of the general population , even after adjustment for age , race , gender , and comorbidities [ 14 ] . in particular , scd has been identified as an important contributor of mortality .
scd is the single largest cause of death in hd patients responsible for 2229  % of all - cause mortality [ 13 , 5 ] .
given the extremely high incidence of cv diseases as well as the case fatality rate of cardiac events , early identification of individuals at risk for increased cv mortality is clinically highly relevant .
in cardiac diseases ecg is beneficial not only as a diagnostic but also prognostic tool .
t - wave abnormalities are among the most frequently encountered pathologic ecg findings in apparently healthy populations .
for example , the presence of even isolated minor t - wave abnormalities is associated with increased long - term cardiac mortality [ 69 ] .
ecg abnormalities are very common in hd patients , with st - t changes observed in 4060  % . moreover
, volume and electrolyte status can influence various ecg variables , with st - t changes frequently appearing in relation to hd timing and the hd process itself often inducing or potentiating ecg alterations , which additionally might compromise ecg interpretation [ 9 , 10 ] .
the prognostic role of t - wave changes in lead avr has long been underestimated .
several recent studies have validated the role of upright t - wave amplitude in lead avr ( tavr ) as a powerful , independent prognostic predictor of cv mortality in the general population [ 1113 ] as well as in some clinical settings [ 1417 ] . however , neither the prevalence nor the predictive value of a positive tavr has been evaluated in hd patients .
we designed this study to prospectively determine whether tavr was predictive of cv mortality and scd in a group of hd patients .
the exclusion criteria were : hd treatment  less  than 1  month , cardiac pacing , preexcitation , atrial fibrillation , right or left bundle branch block , and noncardiac diseases limiting the chance of a 1-year survival .
all patients gave a written consent , and the studies were approved by members of the local ethics committees .
surface 12-lead resting ecgs were recorded with a computer - based electrocardiograph ( cardioperfect , version 1.1 , cardiocontrol nv , rijswijk , the netherlands ) .
ecgs were conducted the day after a dialysis session while subjects were lying in the supine position and breathing normally after at least 5  min of rest .
positive tavr was defined as a wave with a positive deflection  > 0  mv .
the representative ecgs of positive and negative tavr are presented in fig .  1 .
the width of qrs complex and qt interval were recorded automatically by the ecg machine .
st depression was defined as more than 0.5 drop in st - segment in lead v5 from the isoelectric line .
st elevation in lead avr was defined as the elevation  8  v from the isoelectric line .fig . 
positive tavr was defined as a wave with a positive deflection  > 0  mv .
negative tavr was defined as tavr    0  mm t - wave morphology in lead avr .
positive tavr was defined as a wave with a positive deflection  > 0  mv .
negative tavr was defined as tavr    0  mm the following parameters were measured by automated analyzers at the beginning of the evaluation : serum sodium , potassium , calcium , phosphate , creatinine , urea , haemoglobin , intact parathormone ( pth ) , albumin , c - reactive protein ( crp ) , total cholesterol , high - density lipoprotein ( hdl ) cholesterol and triglycerides ( tg ) .
low - density lipoprotein ( ldl ) cholesterol was calculated using the friedewald equation : ldl ( mg / dl )  =  total cholesterol    hdl    ( triglycerides/5 ) .
cardiac tnt in plasma was measured before dialysis by electrochemiluminescence immunoassay ( elecsys 2010 analyser , roche diagnostics ) with a detection limit of 0.01  g / l .
two - dimensional echocardiographic examination was performed using a 2.5-mhz transducer by the cardiologist who was blinded to the clinical data of the study subjects .
the lvm was calculated according to the formula of devereux and reicheck   and this was indexed for body surface to obtain the lvmi .
all echocardiographic measurements were performed in the morning after dialysis   according to the recommendations of the american society of echocardiography .
all patients were followed for at least 3  years after the day of the baseline assessment or until death or renal transplant .
cv death was defined according to standardized definitions for end point events in cardiovascular trials .
scd was defined according to hemodialysis ( hemo ) trial as witnessed and unwitnessed unexpected deaths , with a preceding duration of symptoms less than 24  h for witnessed deaths , and less than the interval since the last dialysis session for unwitnessed deaths .
when normally distributed , continuous variables were expressed as mean    sd , and as median and range when non - normally distributed .
continuous data were compared using the student t - test when normally distributed and using mann 
categorical data were expressed as frequencies and percentages and were compared using the  test .
linear regression analysis was assessed using the pearson correlation coefficient or spearmans rank correlation coefficient when appropriate . for the survival analysis , patients were divided into tavr negative and tavr positive groups .
if patients underwent renal transplantation they were censored on the day of their last dialysis .
cumulative survival curves were constructed by using the kaplan  meier method for cv mortality and scd .
relationships between baseline parameters and endpoints were analyzed with cox proportional hazard regression analysis . in the univariate analyses ,
explanatory variables with a p value  <  0.01 in the univariate analysis were entered into a multivariate analysis .
the exclusion criteria were : hd treatment  less  than 1  month , cardiac pacing , preexcitation , atrial fibrillation , right or left bundle branch block , and noncardiac diseases limiting the chance of a 1-year survival .
all patients gave a written consent , and the studies were approved by members of the local ethics committees .
surface 12-lead resting ecgs were recorded with a computer - based electrocardiograph ( cardioperfect , version 1.1 , cardiocontrol nv , rijswijk , the netherlands ) .
ecgs were conducted the day after a dialysis session while subjects were lying in the supine position and breathing normally after at least 5  min of rest .
positive tavr was defined as a wave with a positive deflection  > 0  mv .
the representative ecgs of positive and negative tavr are presented in fig .  1 .
the width of qrs complex and qt interval were recorded automatically by the ecg machine .
st depression was defined as more than 0.5 drop in st - segment in lead v5 from the isoelectric line .
st elevation in lead avr was defined as the elevation  8  v from the isoelectric line .fig . 
positive tavr was defined as a wave with a positive deflection  > 0  mv .
negative tavr was defined as tavr    0  mm t - wave morphology in lead avr .
positive tavr was defined as a wave with a positive deflection  > 0  mv .
the following parameters were measured by automated analyzers at the beginning of the evaluation : serum sodium , potassium , calcium , phosphate , creatinine , urea , haemoglobin , intact parathormone ( pth ) , albumin , c - reactive protein ( crp ) , total cholesterol , high - density lipoprotein ( hdl ) cholesterol and triglycerides ( tg ) . low - density lipoprotein ( ldl )
cholesterol was calculated using the friedewald equation : ldl ( mg / dl )  =  total cholesterol    hdl    ( triglycerides/5 ) .
cardiac tnt in plasma was measured before dialysis by electrochemiluminescence immunoassay ( elecsys 2010 analyser , roche diagnostics ) with a detection limit of 0.01  g / l .
two - dimensional echocardiographic examination was performed using a 2.5-mhz transducer by the cardiologist who was blinded to the clinical data of the study subjects .
the lvm was calculated according to the formula of devereux and reicheck   and this was indexed for body surface to obtain the lvmi .
left ventricular hypertrophy ( lvh ) was defined by an lvmi over 131  g / m in males or over 110  g / m in females .
all echocardiographic measurements were performed in the morning after dialysis   according to the recommendations of the american society of echocardiography .
all patients were followed for at least 3  years after the day of the baseline assessment or until death or renal transplant . cv mortality and scd were used as endpoints .
cv death was defined according to standardized definitions for end point events in cardiovascular trials .
scd was defined according to hemodialysis ( hemo ) trial as witnessed and unwitnessed unexpected deaths , with a preceding duration of symptoms less than 24  h for witnessed deaths , and less than the interval since the last dialysis session for unwitnessed deaths .
when normally distributed , continuous variables were expressed as mean    sd , and as median and range when non - normally distributed .
continuous data were compared using the student t - test when normally distributed and using mann 
categorical data were expressed as frequencies and percentages and were compared using the  test .
linear regression analysis was assessed using the pearson correlation coefficient or spearmans rank correlation coefficient when appropriate . for the survival analysis
if patients underwent renal transplantation they were censored on the day of their last dialysis .
cumulative survival curves were constructed by using the kaplan  meier method for cv mortality and scd .
relationships between baseline parameters and endpoints were analyzed with cox proportional hazard regression analysis . in the univariate analyses ,
explanatory variables with a p value  <  0.01 in the univariate analysis were entered into a multivariate analysis .
of the total of 321 hd patients initially identified , 98 patients were excluded due to atrial fibrillation , noncardiac diseases limiting the chance of a 1-year survival , pacemaker rhythm , and bundle branch blocks .
the remaining 223 hd patients ( 115 females and 108 males ) , aged 4782  years ( mean 67.67    6.96 ) , who remained on hd from 2 to 94  months ( mean 40.01    20.34 ) entered the study .
the causes of end - stage renal disease ( esrd ) were diabetes ( n  =  91 ) , chronic glomerulonephritis ( n  =  46 ) , hypertensive nephropathy ( n  =  22 ) , obstructive nephropathy ( n  =  9 ) , polycystic kidney disease ( n  =  9 ) , chronic pyelonephritis ( n  =  6 ) , and unknown ( n  =  40 ) . none of the hd patients received anti - arrhythmics ( class i or iii ) or digitalis . out of 223 patients who qualified for the study , 168 ( 75.3  % ) were taking angiotensin - converting enzyme inhibitors / angiotensin receptor blockers , 159 ( 71.3  % ) beta - blockers , 81 ( 36.3  % ) statins and 118 ( 52.9  % ) calcium blockers .
positive tavr was found in 37 ( 16.6  % ) of all patients with no difference between women and men .
patients with positive tavr were older ( p  <  0.001 ) , more often had a history of mi ( p  =  0.008 ) , had higher prevalence of diabetes mellitus ( p  =  0.012 ) , and were more likely to be on beta - blocker therapy ( p  =  0.019 ) .
with regard to echocardiographic parameters , patients with positive tavr had higher lvmi ( p  <  0.001 ) and lower ef ( p  <  0.001 ) in comparison to patients with negative tavr . with regard to ecg parameters , patients with positive tavr had increased width of qrs complex and qt interval ( p  <  0.001 and p  =  0.007 , respectively ) , higher prevalence of st - segment elevation in lead avr ( p  <  0.001 ) , and higher prevalence of st depression ( p  <  0.001 ) as well as negative t in leads ii and v6 ( p  =  0.002 and p  <  0.001 , respectively ) in comparison to patients with negative tavr .
additionally , patients with positive tavr had higher calcium    phosphate scores ( p  =  0.007 ) and higher tnt levels ( p  <  0.001 ) .
more than 70  % of patients with st elevation in avr had concomitant positive tavr.table  1baseline characteristicsvariableall patientstavr 
 p 
 ( n  =  223)negative ( n  =  186)positive ( n  =  37)men / women ( n)0.940.940.950.843age ( years)69.57    5.9668.31    6.5375.78    6.25<0.001hd duration ( months)67.67    6.9667.29    7.1469.57    5.760.551mi ( % ) 26.022.045.90.008smoking ( % ) 18.418.816.20.411beta - blockers ( % ) 71.368.883.80.019ace / arb75.376.370.30.212statins36.335.540.50.248hypertension ( % ) 75.874.781.10.119diabetes mellitus ( % ) 37.234.461.40.012body mass index ( n)25.97    2,4425.99    2.6925.34    2.240.781heart rate ( b.p.m.)80.3    4.4579.4    4.4284.8    4.66<0.001qrs duration ( ms)107.9    19.47105.4    18.56120.59    17.87<0.001qtc bazett ( ms)432.6    33.5430.9    35.8441.2    29.50.007negative t in lead ii ( % ) 13.410.229.70.002negative t in lead v6 ( % ) 18.813.445.9<0.001st depression ( % ) 25.619.456.8<0.001st elevation in lead avr ( % ) 18.47.573.0<0.001lvmi ( g / m)146.5    45.18143.7    46.22159.8    43.11<0.001ef ( % ) 54.91    7.2155.82    7.2850.29    8.42<0.001haemoglobin ( g / dl)11.25    1.4611.21    1.3911.52    1.790.498sodium ( mmol / l)138.2    2.5138.2    2.6138.0    2.10.627potassium ( mmol / l)5.83   
0.815.84    0.795.76    0.920.654calcium    phosphate product ( mg / dl)48.96    10.3247.28    11.5657.40    9.790.007total cholesterol ( mg / dl)186.3    41.05186.8    41.56183.1    43.80.733ldl cholesterol ( mg / dl)112.3    32.03112.5    33.23111.0    37.680.427hdl cholesterol ( mg / dl)40.41    16.1940.38    16.0840.6    17.620.426triglycerides ( mg / dl)168.8    71.69168.4    69.02170.1    70.10.415albumin ( g / dl)3.81    0.373.83    0.393.76    0.400.252crp ( mg / dl)7.38 ( 0.3219.9)7.09 ( 0.3213.9)9.93 ( 7.3219.9)0.191pth ( pg / ml)379 ( 18.01736)361 ( 18.01736)401 ( 67.71350)0.255troponin t ( g / l)0.057 ( 0.000.813)0.051 ( 0.000.533)0.152 ( 0.000.813)<0.001kt / v ( n)1.442    0.2751.442    0.2811.446    0.2690.402 
 mi myocardial infarction , ace / arb angiotensin - converting enzyme inhibitors / angiotensin receptor blockers , ef ejection fraction , qtc qt interval corrected for heart rate using the bazett formula ( qtc  =  qt/rr ) , lvmi left ventricular mass index , pth partahormon , kt / v number used to quantify hemodialysis dialysis treatment adequacy baseline characteristics 
 mi myocardial infarction , ace / arb angiotensin - converting enzyme inhibitors / angiotensin receptor blockers , ef ejection fraction , qtc qt interval corrected for heart rate using the bazett formula ( qtc  =  qt/rr ) , lvmi left ventricular mass index , pth partahormon , kt / v number used to quantify hemodialysis dialysis treatment adequacy over the mean follow - up period of 25.43    3.56  months ( range 136  months ) , there were 79 all - cause deaths , 54 cv deaths including 25 scd .
the incidence of cv death was as follows : in negative tavr group 18.8  % and in positive tavr group 45.9  % ( p  <  0.001 ) .
the incidence of scd was as follows : in negative tavr group 8.1  % and in positive tavr group 24.3  % ( p  <  0.001 ) .
a kaplan  meier analysis showed that the cumulative incidence of cv mortality was significantly higher in patients with positive compared to negative tavr ( log - rank , p  <  0.001 ; fig .  2 ) .
to control for possible confounders , multivariate analysis was performed using a model consisting of univariate predictors of cardiac mortality .
the results of the univariate and multivariate cox proportional hazard regression analyses are shown in table  2 .
univariate regression analysis showed that age , history of mi , ef , tnt level , heart rate , qrs duration , st - segment elevation in lead avr , and positive tavr were univariate predictors of cv mortality . a multivariate analysis selected age [ hazard ratio ( hr ) 1.71 , p  <  0.001 ] , heart rate [ hr 1.42 , p  =  0.016 ] , and positive tavr [ hr 2.21 , p  =  0.001 ] as independent predictors of cv mortality.fig . 
2kaplan  meier survival plots for cardiovascular mortality in hemodialysis patients stratified by positive and negative t - wave in lead avrtable  2uni- and multivariate predictors of cardiac mortalityparameterunivariate hr ( 95  % ci ) 
 p 
 multivariate hr ( 95  % ci ) 
 p 
 age1.25 ( 1.021.1.41)<0.0011.71 ( 1.511.90)<0.001male gender0.98 ( 0.781.21)0.734diabetes mellitus1.38 ( 0.85 - 1.96)0.133history of mi1.42 ( 0.912.11)0.012lvmi1.28 ( 0.692.35)0.279ef2.35 ( 1.252.77)0.0081.89 ( 0.853.61)0.353troponin t2.14 ( 1.323.07)0.0031.45 ( 0.932.72)0.071calcium  phosphate product1.71 ( 1.072.34)0.228beta - blockers1.09 ( 0.782.67)0.677heart rate ( 10 b.p.m .
increase)1.58 ( 1.052.57)0.0061.42 ( 1.031.44)0.016qrs ( 10  ms increase)1.29 ( 1.171.49)0.010corrected qt interval1.18 ( 0.821.84)0.358negative t in lead ii1.26 ( 0.802.23)0.125negative t in lead v62.11 ( 1.272.97)0.009st depression in lead v51.79 ( 0.713.47)0.296st elevation in lead avr1.73 ( 1.251.89)0.0041.69 ( 0.972.46)0.202positive tavr3.03 ( 2.564.21)<0.0012.21 ( 1.762.79)0.001 in the multivariate analyses , parameters with a p    0.01 were entered 
 hr hazard ratio , ci confidence interval , mi myocardial infarction , lvmi left ventricular mass index , ef ejection fraction kaplan  meier survival plots for cardiovascular mortality in hemodialysis patients stratified by positive and negative t - wave in lead avr uni- and multivariate predictors of cardiac mortality in the multivariate analyses , parameters with a p    0.01 were entered 
 hr hazard ratio , ci confidence interval , mi myocardial infarction , lvmi left ventricular mass index , ef ejection fraction kaplan 
meier sub analyses were performed to assess the prognostic value of tavr with regard to scd .
figure  3 shows that the cumulative incidence of scd was significantly higher in patients with negative compared to positive tavr ( log - rank , p  <  0.001 ) . to control for possible confounders ,
the results of the univariate and multivariate cox proportional hazard regression analyses are shown in table  3 .
univariate regression analysis showed that age , history of mi , lvmi , tnt , and positive tavr were univariate predictors of scd .
after controlling for univariate predictors of scd age [ hr 1.88 , p  <  0.001 ] , and positive tavr [ hr 1.53 , p  =  0.014 ] remained independent predictors of scd.fig . 
3kaplan  meier survival plots for sudden cardiac death in hemodialysis patients stratified by positive and negative t - wave in lead avrtable 
3uni- and multivariate predictors of sudden cardiac deathparameterunivariate hr ( 95  % ci ) 

p 
 multivariate hr ( 95  % ci ) 
 p 
 age1.15 ( 1.071.30)<0.0011.88 ( 1.452.03)<0.001male gender1.08 ( 0.691.47)0.804diabetes mellitus0.88 ( 0.252.37)0.533history of mi1.84 ( 1.132.98)0.035lvmi1.44 ( 1.142.21)0.018ejection fraction2.14 ( 1.192.68)0.0092.35 ( 0.973.87)0.294troponin t1.64 ( 1.022.97)0.014calcium x phosphate product1.01 ( 0.372.17)0.245beta - blockers0.95 ( 0.332.47)0.714heart rate ( 10 b.p.m .
increase)1.33 ( 0.982.47)0.203qrs ( 10  ms increase)1.19 ( 0.871.66)0.253corrected qt interval1.48 ( 0.912.74)0.309negative t in lead ii1.67 ( 0.762.53)0.311negative t in lead v61.43 ( 1.862.57)0.023st depression in lead v51.33 ( 0.613.37)0.325st elevation in lead avr2.23 ( 0.873.49)0.076positive tavr2.54 ( 2.123.59)0.0011.53 ( 1.122.74)0.014 in the multivariate analyses , parameters with a p    0.01 were entered 
 hr hazard ratio , ci confidence interval , mi myocardial infarction , lvmi left ventricular mass index , ef ejection fraction kaplan  meier survival plots for sudden cardiac death in hemodialysis patients stratified by positive and negative t - wave in lead avr uni- and multivariate predictors of sudden cardiac death in the multivariate analyses , parameters with a p    0.01 were entered 
 hr hazard ratio , ci confidence interval , mi myocardial infarction , lvmi left ventricular mass index , ef ejection fraction
this study showed that tavr analysis provides prognostic information for hd patients beyond what is available from other known traditional risk factors .
the presence of positive tavr remained an independent and powerful predictor of cv mortality as well as scd even after adjustment for established cv risk factors .
positive tavr was superior to any other ecg findings in the identification of patients most at risk for cardiac events .
the kaplan  meier curves began to separate early and then continued to stay separate until the end of follow - up for both cv mortality and scd .
lead avr often yields information from the right upper side of the heart that is not as readily available from other leads . when repolarization of injured myocardial cells is delayed compared to normal cells , the direction of the t - wave vector changes towards the injured myocardial region .
thus , positive t - waves in lead avr might represent the presence of ischemically injured myocardium in the apical , inferior , and lower lateral regions of the heart .
these areas of the heart are supplied with blood from left anterior descending ( lad ) , right coronary , or left circumflex coronary artery .
therefore , disease of these arteries or lesions located more proximally in left main coronary artery ( lmca ) would be expected to positively invert a normally negative tavr [ 21 , 23 ] .
the prevalence of positive tavr in our study ( 16.6  % ) was higher than the general population ( 2.2  % ) , and comparable to the prevalence of positive tavr in patients with heart failure ( 17.5  % )   and prior myocardial infarction ( 16.2  % ) .
previous studies have found that positive tavr is associated with lmca disease , multivessel disease , and proximal lad occlusion [ 1416 , 21 , 23 ] .
moreover , multivessel disease is observed in most cases and lmca disease is also very common in hd patients [ 24 , 25 ] .
however , in our study tavr was associated with cv events independent of tnt which is good surrogate marker of myocardial injury .
it may be due to the fact that tnt elevation in hd patients may result from reduced renal clearance , direct injury to myocardial cells ( toxins , hypoxia , stretching ) , reversible myocardial ischaemic release in the absence of myocardial necrosis and , from lvh .
elevated tnt levels have been observed in 3075  % of hd patients in the absence of an acute myocardial injury .
our results are in agreement with some previous studies indicating that the predictive accuracy of ef for cv events is limited . in our study
more than 70  % of patients with st - segment elevation in lead avr also had positive tavr .
that st - segment elevation in lead avr is predictive of cardiac mortality only when not accounting for positive tavr .
the effect of st - segment elevation in lead avr predicting cardiac events can be attributed in part to the presence of positive tavr .
the prognostic utility of upright tavr for predicting cv mortality in hd patients is in concordance with previous studies that have documented that positive tavr is a powerful marker for estimating risk of cv death both in the general population [ 12 , 13 ] as well as in some clinical settings such as heart failure , acute coronary syndromes , or myocardial infarction [ 14 , 15 , 28 , 29 ] . to our knowledge , this is the first study that has demonstrated the prognostic utility of upright tavr for predicting scd . given the ubiquity , inexpensiveness and convenience of ecg recordings and the fact that scd is the single largest cause of death in hd patients [ 13 , 5 ] , the results of tavr might be readily utilized for scd risk estimation in hd patients .
it currently remains unclear whether upright tavr is merely a marker of poor prognosis that reflects the high prevalence of the most severe forms of coronary artery disease , contributing to cv mortality , including scd , or whether it potentially identifies more distinct electrophysiological mechanisms that underlie increased mortality and scd .
nevertheless , the population was large enough to demonstrate a predictive value for a positive tavr .
second , the exclusion of patients with some clinical conditions potentially associated with a higher mortality , such as atrial fibrillation , may also add bias to the results .
third , it is possible that serial rather than single measurements of tavr may have changed the results , making tavr either more or less useful in predicting clinical events in hd patients .
positive tavr is associated with increased cv mortality as well as scd in hd patients .
this simple ecg parameter provides additional information beyond what is available with other known traditional risk factors and allows the identification of patients most at risk of cv events .
hd patients with a positive tavr , should be considered for additional diagnostic and preventive measures .
 backgroundgiven that cardiac disease is the leading cause of mortality in hemodialysis ( hd ) patients , identification of patients at risk for cardiac mortality is crucial . 
 the aim of this study was to determine if positive t - wave amplitude in lead avr ( tavr ) was predictive of cardiovascular ( cv ) mortality and sudden cardiac death ( scd ) in a group of hd patients.methods and resultsafter exclusion , 223 hd patients were prospectively followed - up for 25.43    3.56  months . 
 patients were divided into tavr negative ( n  =  186 ) and tavr positive ( n  =  37 ) groups . 
 myocardial infarction , diabetes and beta - blocker therapy were more frequent in positive tavr patients . 
 patients with upright tavr were older , had higher left ventricular mass index , lower ejection fraction , higher calcium    phosphate product , higher troponin t level , higher prevalence of st - t abnormalities , and increased width of qrs complex and qt interval , compared with patients with negative tavr . 
 a kaplan  meier analysis showed that the cumulative incidences of cv mortality as well as scd were higher in patients with positive tavr compared with those with negative tavr ( log - rank , p  <  0.001 in both cases ) . 
 a multivariate analysis selected age [ hazard ratio ( hr ) 1.71 , p  <  0.001 ] , heart rate ( hr 1.42 , p  =  0.016 ) , and positive tavr ( hr 2.21 , p  =  0.001 ) as well as age ( hr 1.88 , p  <  0.001 ) , and positive tavr ( hr 1.53 , p  =  0.014 ) as independent predictors of cv mortality and scd , respectively.conclusionin hd patients , positive tavr is an independent and powerful predictor of cv mortality as well as scd . 
 this simple ecg parameter provides additional information beyond what is available with other known traditional risk factors and allows the identification of patients most at risk of cv events . 
Introduction
Materials and methods
Patients
Electrocardiography
Biochemical measurements
Echocardiographic examination
Follow-up data
Statistical analysis
Results
Discussion
Study limitations
Conclusions