Ashwini Davison
Justin Dunn
Jason Mock
Deepa Rangachari
May 13, 2009
Types of Trials
 Controlled Study
 - Randomize Control Trial (RCT) – type of scientific experiment most
commonly used in testing the efficacy or effectiveness of healthcare services or
technologies.

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With sufficient numbers, this ensures that both known and unknown
confounding factors are evenly distributed between treatment groups.
Considered the most reliable form because they eliminate spurious causality and
bias.
 Observational Study
 Cohort study - group of people who share a common characteristic or
experience within a defined period.
 Case Control - Studies used to identify factors that may contribute to a medical
condition by comparing subjects who have that condition with patients
who do not have the condition but are otherwise similar
 Case Series
Definition of Case Series
 Descriptive research study that tracks patients with a
known exposure given similar treatment or examines
their medical records for exposure and outcome.
 Also known as clinical series
 Can be retrospective or prospective
 Smaller number of patients than more
powerful case-control or RCTs
Case Series
 Provide information when other types cannot or
should not be undertaken
 Case series may be confounded by selection bias,
which limits statements on the causality of
correlations observed
 Results of case series can generate hypotheses that
could be useful in designing further studies
 In this article the authors use a case series to ask the
question what clinically (in the ED) can be used to
differentiate Takotsubo cardiomyopathy versus STsegment elevation myocardial infarction
What is Takotsubo cardiomyopathy?
 Also known as left ventricular apical ballooning
syndrome, ampulla CM, stress CM
 Develop anginal symptoms and CHF in times of stress
 Extreme: acute pulmonary edema, cardiogenic shock
EKG & Labs
 ST segment and/or T wave abnormalities
 Similar to what’s seen in STEMI
 Serum markers may be elevated
Cath & ventriculogram
 Catheterization: abnormal LV function, but NORMAL
coronary arteries
Diastole
Systole
Diagnostic criteria (Mayo)
 1) transient LV apical akinesis or dyskinesis
 2) absence of obstructive CAD
 3) new EKG abnormalities in absence of concurrent
conditions
How Patients Were Selected
 Reviewed 12 consecutive cases of Takotsubo CM that
presented to UVA
 3 case excluded because of incomplete data
 Then took 9 consecutive cases of STEMI for
comparison
 18 cases total (9 TCM, 9 STEMI)—same time period
 Comparisons made between 2 groups
Demographic Results
Descriptor
Takotsubo
STEMI
% that were female
89
44
Average age (years)
68.2
65.1
% with chest pain
88.9
100
% with dyspnea
55.6
77.8
% with nausea/vomiting
33.3
88.9
% with diaphoresis
55.6
100
EKG Comparisons
EKG abnormality
Takotsubo
STEMI
ST-segment elevation
66.7%
100%
Inferior
0
55.6
Lateral
11.1
33.3
Anterior
55.6
33.3
33.3%
77.8%
Inferior
22.2
33.3
Lateral
11.1
22.2
Anterior
0
33.3
T wave inversion
66.7%
33.3%
QT prolongation
451 ms
433 ms
ST-segment depression
Other comparisons
 CXR findings were similar in both groups
 Initial troponin elevation similar
 STEMI peak troponin 7.34 vs TCM with 4.91
 EF on echo—32.7% in Takotsubo, vs 25.2% in STEMI
Design
 Not really a case series by definition—used control
group (STEMI patients)
 A number of case series were published prior (all with
9 or more pts), and a systematic review published in
2006.
 Appears to be a case series of Takotsubo compared
with a case series of STEMIs.
Strengths
 Used consecutive patients to help reduce selection bias
in both groups (though did exclude 3 from case group)
 All patients were (we assume) at the same institution
Weaknesses
 Time frame? Unclear how long to select patients; also
unclear how STEMI pts selected.
 Too few patients—9 in each group.
 No distribution of values given, no hard data—only
means/percentages, no medians.
 No p values or confidence intervals
Weaknesses
 3 people eliminated in case group for “incomplete
data”—contribute to selection bias?
 No risk factors noted in either group
 Unclear if any question was answered.
Conclusions
 Takotsubo CM often mimics ACS
 Anginal chest pain with acute heart failure
 This retrospective case series shows its difficult to
distinguish the 2 in the ER
Take Home Message
 Physicians need to be aware of this alternative
diagnosis to a STEMI
 Still need to watch for dysrhythmias & cardiogenic
shock with
 Ideally, if Takotsubo CM suspectedcardiac
catheterization should be chosen over fibrinolytics
Further Discussion
 Dr. Hunter Young, former Barker ACS