Characteristics and clinical outcome of 458 patients with acute myocardial infarction requiring mechanical ventilation. Results of the BEAT registry of the ALKK-study group.

Abstract

Information about the clinical course of patients with acute myocardial infarction requiring mechanical ventilation is scarce. We sought to evaluate the clinical outcome of a large cohort of such patients in clinical practice.
The German BEAT registry prospectively enrolled consecutive patients requiring mechanical ventilation who were admitted to an internal intensive care unit (ICU) of 45 participating German hospitals between September 2001 and June 2002. For this analysis, we created a subgroup of patients with acute ST-segment-elevation or non-ST-segment-elevation myocardial infarction.
During the 9-month study period, 458 consecutive patients fulfilled our inclusion criteria. The mean age was 68 ± 8 years and 71% were men. 40% of the patients were already intubated in the prehospital phase. The initial reason for intubation was in 48% of the cases ventricular fibrillation/tachycardia or sudden cardiac death, in 39% congestive heart failure and in 13% of the cases non-cardiac. The median time of ventilation was 2 days (1-5) among survivors and 1 day (0-5) among non-survivors. Of the 458 patients, 256 (56%) had already or developed cardiogenic shock, 86 (19%) acute renal failure, 76 (17%) coma or brain damage, 64 (14%) severe infection, 46 (10%) sepsis and 28 (6%) multiorgan distress syndrome; 11% were treated with fibrinolysis, 39% with PCI and 6% with coronary artery bypass grafting. The overall hospital mortality rate was 48%. In patients with cardiogenic shock, mortality was even higher with 69%.
Patients requiring mechanical ventilation during an acute myocardial infarction constitute a high risk group with a mortality of about 50%. Further research is necessary to improve the outcome of these patients.

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Clinical Research in
Cardiology

ISSN 1861-0684
Volume 100
Number 3

Clin Res Cardiol (2010)
100:235-239
DOI 10.1007/
s00392-010-0235-6
Characteristics and clinical outcome
of 458 patients with acute myocardial
infarction requiring mechanical
ventilation. Results of the BEAT registry of
the ALKK-study group

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123
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ORIGINAL PAPER
Characteristics and clinical outcome of 458 patients with acute
myocardial infarction requiring mechanical ventilation. Results
of the BEAT registry of the ALKK-study group
Kleopatra Kouraki•Steffen Schneider•Rainer Uebis•
Ulrich Tebbe•Hermann H. Klein•Uwe Janssens•
Ralf Zahn•Jochen Senges•Uwe Zeymer
Received: 28 June 2010/Accepted: 7 September 2010/Published online: 29 September 2010
? Springer-Verlag 2010
Abstract
Background
patients
mechanical ventilation is scarce. We sought to evaluate the
clinical outcome of a large cohort of such patients in
clinical practice.
Methods
The German BEAT registry prospectively
enrolled consecutive patients requiring mechanical venti-
lation who were admitted to an internal intensive care unit
(ICU) of 45 participating German hospitals between Sep-
tember 2001 and June 2002. For this analysis, we created a
subgroup of patients with acute ST-segment-elevation or
non-ST-segment-elevation myocardial infarction.
Information about the clinical course of
acutemyocardialwithinfarctionrequiring
Results
tive patients fulfilled our inclusion criteria. The mean age
was 68 ± 8 years and 71% were men. 40% of the patients
were already intubated in the prehospital phase. The initial
reason for intubation was in 48% of the cases ventricular
fibrillation/tachycardia or sudden cardiac death, in 39%
congestive heart failure and in 13% of the cases non-car-
diac. The median time of ventilation was 2 days (1–5)
among survivors and 1 day (0–5) among non-survivors. Of
the 458 patients, 256 (56%) had already or developed
cardiogenic shock, 86 (19%) acute renal failure, 76 (17%)
coma or brain damage, 64 (14%) severe infection, 46
(10%) sepsis and 28 (6%) multiorgan distress syndrome;
11% were treated with fibrinolysis, 39% with PCI and 6%
with coronary artery bypass grafting. The overall hospital
mortality rate was 48%. In patients with cardiogenic shock,
mortality was even higher with 69%.
Conclusions
Patients requiring mechanical ventilation
during an acute myocardial infarction constitute a high risk
group with a mortality of about 50%. Further research is
necessary to improve the outcome of these patients.
During the 9-month study period, 458 consecu-
Keywords
ventilation ? Intensive care unit ? Mortality ? Outcome
Myocardial infarction ? Mechanical
Introduction
Information about the mortality of critically ill patients is
important, because it might help to improve patient man-
agement and allows for better counseling of patients and
their families. The mortality of critically ill patients
requiring mechanical ventilation on an intensive care unit
(ICU) has been widely studied in various heterogeneous [1]
and specific patient groups, mostly those with acute
For the ALKK-study group (Arbeitsgemeinschaft Leitender
Kardiologischer Krankenhausa ¨rzte).
K. Kouraki ? R. Zahn ? U. Zeymer (&)
Herzzentrum Ludwigshafen, Bremserstrasse 79,
67063 Ludwigshafen, Germany
e-mail: Uwe.Zeymer@t-online.de
S. Schneider ? J. Senges ? U. Zeymer
Institut fu ¨r Herzinfarktforschung Ludwigshafen
an der Universita ¨t Heidelberg, Ludwigshafen, Germany
R. Uebis
Klinikum Aschaffenburg Med. Klinik I,
Aschaffenburg, Germany
U. Tebbe
Klinikum Lippe Detmold Med. Klinik II, Detmold, Germany
H. H. Klein
Idar-Oberstein Kardiologie, Idar-Oberstein, Germany
U. Janssens
Klinikum Eschweiler Kardiologie, Eschweiler, Germany
123
Clin Res Cardiol (2011) 100:235–239
DOI 10.1007/s00392-010-0235-6
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respiratory distress syndrome (ARDS) or acute exacerba-
tion of chronic obstructive pulmonary disease (COPD).
However, little is known about the epidemiologic charac-
teristics, clinical course and outcome of patients with
mechanical ventilation initially admitted with an acute
myocardial infarction. Our aim was to prospectively
identify and describe the characteristics, clinical course and
outcome of all consecutive patients admitted in 45 cardi-
ological or medical ICUs across Germany with acute
myocardial infarction requiring mechanical ventilation.
Methods
The BEAT (Beatmung = ventilation) registry prospec-
tively enrolled all consecutive patients admitted to an ICU
requiring mechanical ventilation between September 2001
and June 2002. All 45 participating ICUs were internal or
cardiological, no mixed- or surgical ICUs were included.
Of the 45 participating hospitals, 33 were members of the
ALKK-study group (Arbeitsgemeinschaft Leitender Kar-
diologischer Krankenhausa ¨rzte) and 12 were university
hospitals. All consecutive patients meeting the above cri-
teria were included, regardless of the intubation site, the
duration or the type of mechanical ventilation. The study
design was observational; comparison of various ventila-
tion methods or interventional strategies was not intended.
Acute myocardial infarction was defined as ST-elevation
myocardial infarction or non-ST-elevation myocardial
infarction 24 h prior to admission.
Clinical data were obtained with the use of a two-part
questionnaire, filled out by the ICU physician on admission
and at hospital discharge or death. The first part of the
questionnaire included demographic data, information
regarding the site of the initial intubation, the cause of
intubation, existing comorbidities as well as acute com-
plications. The second part included duration and type of
ventilation, complications, the therapies during ICU stay
(medical, interventional, and surgical) and the length of
stay in the ICU. Patients were followed until hospital dis-
charge. The main target of this analysis was to describe all-
cause hospital mortality.
Statistical analysis
Data from the 45 participating ICUs were centrally col-
lected and analyzed at the statistical department of ‘‘Institut
fu ¨r Herzinfarktforschung Ludwigshafen an der Universita ¨t
Heidelberg’’, Ludwigshafen, Germany. Data are presented
as absolute numbers, percentage or medians with 25th and
75th percentiles as appropriate. We assessed differences of
categorical variables using chi-square tests and continuous
variables using Wilcoxon rank-sum test. Values of
p\0.05 were considered significant. Odds ratios (ORs)
and 95% confidence intervals (CI) were calculated, using
the statistical analysing package SAS?system release 8.2.
Results
Of the 2,363 patients included in the registry, we retro-
spectively identified 458 who were initially admitted with
acute myocardial infarction. The median age was 68 years
(interquartile range 60–76 years) and 70.7% were men.
Median ventilation length was 2 days (interquartile range
1–5 days) and median ICU stay was 20 days (interquartile
range 13–26 days). Forty percent of the patients were
intubated in a prehospital setting, 60% in the hospital; 85%
of the intubations were urgent, 15% elective. The main
ventilation method after intubation as well as for the main
period of ventilation was BIPAP (bilevel positive airway
pressure) followed by CPPV (continuous positive pressure
ventilation). Initial cause of intubation as well as detailed
type of ventilation is given in Table 1. Tracheotomy was
performed on 28 patients (6%), on 15 patients percutane-
ously, on 13 patients surgically.
During ICU stay, 364 (79%) patients were given vaso-
pressors, 253 (55%) antibiotic treatment and 81 (18%)
received at least one blood transfusion. Acute reperfusion
therapy with fibrinolysis was performed in 49 (11%) of the
patients, 177 (39%) were treated with percutaneous coro-
nary intervention and 31 (6%) with coronary artery bypass
grafting.
Of the 458 patients, 256 (56%) developed cardiogenic
shock, 86 (19%) acute renal failure, 76 (17%) coma or
brain damage, 64 (14%) severe infection, 46 (10%) sepsis,
28 (6%) multiorgan distress syndrome (MODS), 17 (4%)
gastrointestinal bleeding and 6 (1%) ARDS.
The overall mortality rate for the cohort was 48% (220/
458). Patients who died were significantly older than those
who survived (71.2 ± 6.9 vs. 68.2 ± 8.1 years, p\0.01).
No significant difference in mortality was noted between
men and women. Mortality rates were higher for those
intubated in the hospital (53%), especially on the ICU
(58%) as compared to those intubated out of hospital
(40%). A significantly increased mortality was observed
among patients requiring CPPV initially (61%) as well for
the main period of ventilation (79%).
In the univariate analysis, mortality rates were signifi-
cantly higher among patients who developed cardiogenic
shock, sepsis, acute renal failure and ARDS. The occur-
rence of a gastrointestinal bleeding, a severe infection or a
cerebrovascular insult did not statistically significant
influence a lethal outcome. Mortality rates of patients
developing severe complications on the ICU are shown in
Fig. 1.
236Clin Res Cardiol (2011) 100:235–239
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Discussion
Inthisprospective,multi-center,observationalstudywith458
consecutive mechanically ventilated patients initially admit-
ted with an acute myocardial infarction, the overall mortality
was 48%. The need for mechanical ventilation identifies a
high risk subgroup of patients with acute myocardial infarc-
tion. The widespread use of aspirin, fibrinolytic drugs and
coronary interventions such as the introduction of coronary
care units has substantially reduced hospitalmortality rates in
acute myocardial infarction. Despite this profound decline in
case-fatality compared to the mid 1960s when the in-hospital
mortalityratesaveraged25–30%[2],thefactorsthatinfluence
the overall outcome seem to remain the same, namely age,
large size of infarction, site of infarction, low blood pressure
on admission and higher Killip class on admission [3]. The
highest mortality is still seen in patients with cardiogenic
shock [4, 5]. However, little is known about the influence of
mechanical ventilation on the clinical course and outcome of
patients admitted with acute myocardial infarction.
Table 1 Baseline patient characteristics, cause of intubation and type of ventilation
All
(n = 458)
Survivors
(n = 238)
Non-survivors
(n = 220)
OR
(95% CI)
p value
Age (years)68.2 (59.9–76.3) 66.8 (57.3–74.5)71.2 (61.8-78.3)
\0.01
0.47Men 70.7% 72.2% 69.1%0.86 (0.58–1.29)
Resuscitation 173 (38%)92 (38%)81 (37%) 0.92 (0.63–1.35) 0.69
Reason for intubation
Ventricular arrhythmia/sudden cardiac death222 (48%)116 (49%)106 (48%)0.89 (0.60–1.33)0.23
Congestive heart failure180 (39%)90 (38%)90 (41%)1.08 (0.73–1.59)
Shock 27 (6%)12 (5%)15 (7%)2.71 (0.79–9.26)
Non-cardiac 29 (6%)20 (8%) 9 (4%)1.20 (0.07–19.63)
Initial type of ventilation
CPPV150 (33%)58 (24%)92 (42%) 2.18 (1.46–3.25)
\0.001
BIPAP220 (48%)129 (54%)91 (41%)0.57 (0.40–0.83)
BIPAP/SIMV 18 (4%)11 (5%)7 (3%)0.67 (0.25–1.75)
SIMV/ASB40 (9%) 22 (9%)18 (8%)0.86 (0.45–1.65)
CPAP/ASB 15 (3%)12 (5%)3 (1%)0.26 (0.07–0.92)
Main type of ventilation
CPPV91 (20%) 19 (8%)72 (33%)5.50 (3.19–9.51)
\0.0001
BIPAP187 (41%)101 (42%)86 (39%)0.85 (0.58–1.23)
BIPAP/SIMV 22 (5%)16 (7%)6 (3%)0.38 (0.15–0.99)
SIMV/ASB54 (12%)33 (14%)21 (10%)0.64 (0.36–1.15)
CPAP/ASB69 (15%)52 (22%) 17 (8%)0.29 (0.16–0.53)
CPPV continuous positive pressure ventilation, BIPAP bilevel positive airway pressure, SIMV synchronized intermittent mandatory ventilation,
ASB assisted spontaneous breaths, CPAP continuous positive airway pressure
48%
69%
71%
74%
92%
0%
20%
40%
60%
80%
100%
overall
mortality
cardiogenic
shock
sepsis
acute renal
failure
MODS
Fig. 1 Hospital mortality in the
entire group and subgroups with
severe complications (MODS
multi-organ distress syndrome)
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Three retrospective studies have shown a high mortality
rate among such patients. Lo ´pez Messa et al. [6] reported in
2001 a 65.7% mortality rate among 333 mechanically
ventilated patients with acute myocardial infarction in a
retrospective analysis from the Spanish registry ARIAM
(Ana ´lisis Retraso Infarto Agudo Miocardio). The patients
who died were older, more frequently female, had been
more frequently admitted to the coronary unit, and more
often had Killip IV on admission. Zagher et al. [7]
described in 2005 a 30-day mortality of 29% and a 1-year
mortality of 46% in a retrospective cohort of 267 consec-
utive patients admitted to the coronary care unit for an
acute coronarysyndrome
mechanical ventilation. Parameters found to be indepen-
dent predictors were in descending order vasopressor
requirement, use of antibiotics, peripheral vascular disease,
ST-elevation myocardial infarction, renal failure, obesity
and higher Killip class on admission. Lesage et al. [8]
performed in 2004 a retrospective chart-based analysis of
157 consecutive ventilated patients with AMI which
received coronary reperfusion therapy within 12 h fol-
lowing symptom onset. 28-day ICU mortality rate was 51%
and the main risk factors for death were high APACHE II
score, early development of acute renal failure and low
resting left ventricular function. Although the different
inclusion criteria and therapeutic approaches unavoidably
resulted in different patient populations and outcomes, a
common parameter found in these three reports is a high
mortality rate ranging 29–66%.
Our findings confirm the high mortality rates among
patients with acute myocardial infarction that require
mechanical ventilation. In our analysis, the following
subgroups were associated with higher mortality rates:
Older age, intubation on the ICU, need for long-term
CPPV-ventilation, need for a repeat intubation after initial
weaning, development of cardiogenic shock, acute renal
failure, sepsis, MODS and need for vasopressor treatment.
Mortality rate was 56% for patients in need of vasopressor
treatment and increased with each severe complication,
namely 69% for cardiogenic shock, 71% for sepsis, 74%
for acute renal failure and 92% for MODS. As expected,
these mortality rates are markedly higher than those pre-
viously documented for cardiogenic shock from all causes
[9], acute renal failure in the ICU [10] and severe sepsis in
the ICU [11, 12], as they represent a much sicker cohort.
Interestingly enough, there seems to be similar mortality
rates among our patients and patients which had to be
intubated and mechanically ventilated in the setting of an
intensive care unit of a tertiary hospital for other causes,
such as 56% overall in-hospital mortality for community-
acquired pneumonia [13], 52.9% in-hospital mortality for
acute COPD-exacerbation [14] and 70% 1-year mortality
in patients with acute ischemic stroke [15]. Although
whorequired[3 daysof
mechanical ventilation is undoubtedly a lifesaving proce-
dure for critically ill patients, it is at the same time an
indicator of a worse clinical outcome, regardless of the
initial cause of intubation.
The relatively small number of patients in whom a
coronary angiography was performed (204/458, 45%) can
be explained by the severity of illness of some of the
patients, which were not regarded eligible for an inter-
ventional approach in combination with the early stabil-
ization and extubation of others, which were transferred to
a standard cardiology ward for further treatment. Patients
who were selected to receive early revascularization with
percutaneous coronary intervention or coronary artery
bypass grafting while still on ICU had a reduced mortality
rate of 41% (p\0.01) and 19%, respectively, similar to
that reported by Lesage et al. [8]. Those patients who
received coronary angiography even without revasculari-
zation had a lower mortality rate as well, suggesting that
selection bias plays an important role in determining out-
comes [9, 16].
Limitations
This is the first study to prospectively enroll such a large
number of consecutive patients with acute myocardial
infarction in need of mechanical ventilation. However, the
initial purpose of the BEAT register was the enrollment of
all consecutive patients requiring mechanical ventilation on
45 intensive care units, so that specific cardiological data
such as left ventricular function, time to intervention or
extent of the coronary artery disease are missing. Fur-
thermore, predictors of mortality cannot accurately be
determined based on registry data, especially of this
heterogeneity.
Conclusions
The need for mechanical ventilation in patients undergoing
an acute myocardial infarction is a significant predictor of
increased mortality. Mortality was not influenced by the
initial cause of intubation or the need for cardiac resusci-
tation. The main risk factors for increased mortality in this
cohort were older age, mode of ventilation and develop-
ment of severe complications. These results of a large
cohort of patients enrolled in a large number of hospitals
confirm findings from previous smaller cohorts. There are
almost no data available on the optimal mode and time of
ventilation in patients with acute myocardial infarction.
Guidelines are mostly based on expert opinions than on
data. Therefore, further research is urgently needed to
improve the outcome of these high risk patients with acute
myocardial infarction.
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References
1. Esteban A, Anzueto A, Frutos F, Inmaculada A, Brocard L,
Stewart T, Benito S, Epstein S, Apeyteguı ´a C, Nightingale P,
Arroliga A, Tobin M (2002) Characteristics and outcomes in
adultpatientsreceiving mechanical
287:345–355
2. Norris RM, Caughey DE, Mercer CJ, Scott PJ (1974) Prognosis
after myocardial infarction. Six-year follow-up. Br Heart J
36(8):786–790
3. Van de Werf F, Ardissino D, Betriu A, Cokkinos DV, Falk E, Fox
KA, Julian D, Lengyel M, Neumann FJ, Ruzyllo W, Thygesen C,
Underwood SR, Vahanian A, Verheugt FW, Wijns W, Task
Force on the Management of Acute Myocardial Infarction of the
European Society of Cardiology (2003) Management of acute
myocardial infarction in patients presenting with ST-segment
elevation. The Task Force on the Management of Acute Myo-
cardial Infarction of the European Society of Cardiology. Eur
Heart J 24(1):28–66
4. Hochman JS, Sleeper LA, Webb JG, Sanborn TA, White HD,
Talley JD, Buller CE, Jacobs AK, Slater JN, Col J, McKinlay
SM, LeJemtel TH (1999) Early revascularization in acute myo-
cardial infarction complicated by cardiogenic shock. N Engl J
Med 341:625–634
5. Zeymer U, Vogt A, Zahn R, Weber MA, Tebbe U, Gottwik M,
Bonzel T, Senges J, Neuhaus KL (2004) Predictors of in-hospital
mortality in 1333 patients with acute myocardial infarction
complicated by cardiogenic shock treated with primary percuta-
neous coronary intervention. Eur Heart J 25:322–328
6. Lo ´pez Messa JB, Andre ´s de Llano JM, Berrocal de la Fuente CA,
Pascual Palacı ´n R, por el Grupo ARIAM (Ana ´lisis Retraso Infarto
Agudo Miocardio) (2001) Patient characteristics of acute myo-
cardial infarction in mechanical ventilation. Data from Spanish
registry ARIAM. Rev Esp Cardiol 54:851–859
7. Zahger D, Maimon N, Novack V, Wolak A, Friger M, Gilutz H,
Ilia R, Almog Y (2005) Clinical characteristics and prognostic
factors in patients with complicated acute coronary syndromes
requiring prolonged mechanical ventilation. Am J Cardiol
96:1644–1648
ventilation.JAMA
8. Lesage A, Ramakers M, Daubin C, Verrier V, Beynier D,
Charbonneau P, du Cheyron D (2004) Complicated acute myo-
cardial infarction requiring mechanical ventilation in the inten-
sive care unit: prognostic factors of clinical outcome in a series of
157 patients. Crit Care Med 32:100–105
9. Hochman JS, Buller CE, Sleeper LA, Boland J, Dzavik V, San-
born TA, Godfrey E, White HD, Lim J, LeJemtel T (2000)
Cardiogenic shock complicating acute myocardial infarction—
etiologies, management and outcome: a report from the SHOCK
Trial Registry. J Am Coll Cardiol 36:1063–1070
10. de Mendonc ¸a A, Vincent JL, Suter PM, Moreno R, Dearden NM,
Antonelli M, Takala J, Sprung C, Cantraine F (2000) Acute renal
failure in the ICU: risk factors and outcome evaluated by the
SOFA score. Intensive Care Med 26(7):915–921
11. Harrison DA, Welch CA, Eddleston JM (2006) The epidemiology
of severe sepsis in England, Wales and Northern Ireland,
1996–2004: secondary analysis of a high quality clinical data-
base, the ICNARC Case Mix Programme Database. Crit Care
10(2):R42
12. Za ´horec R, Firment J, Strakova ´ J, Mikula J, Malı ´k P, Nova ´k I,
Zeman J, Chlebo P (2005) Epidemiology of severe sepsis in
intensivecare unitsin the
33(3):122–128
13. Lee JH, Ryu YJ, Chun EM, Chang JH (2007) Outcomes and
prognostic factors for severe community-acquired pneumonia
that requires mechanical ventilation. Korean J Intern Med
22(3):157–163
14. Ucgun I, Metintas M, Moral H, Alatas F, Yildirim H, Erginel S
(2006) Predictors of hospital outcome and intubation in COPD
patients admitted to the respiratory ICU for acute hypercapnic
respiratory failure. Respir Med 100(1):66–74
15. Milhaud D, Popp J, Thouvenot E, Heroum C, Bonafe ´ A (2004)
Mechanical ventilation in ischemic stroke. J Stroke Cerebrovasc
Dis 13:183–188
16. Koeth O, Zahn R, Heer T, Klein B, Bauer T, Ju ¨nger C, Gitt AK,
Senges J, Zeymer U (2009) Gender differences in patients with
acute ST-elevation myocardial infarction complicated by car-
diogenic shock. Clin Res Cardiol 98:781–786
Slovak Republic.Infection
Clin Res Cardiol (2011) 100:235–239239
123
Author's personal copy