Takotsubo Cardiomyopathy versus ST-segment elevation MI

—A case seriesAshwini Davison

Justin DunnJason Mock

Deepa Rangachari

May 13, 2009

Types of TrialsControlled Study

- Randomize Control Trial (RCT) – type of scientific experiment most commonly used in testing the efficacy or effectiveness of healthcare services or technologies. 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 SeriesDescriptive 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 seriesCan be retrospective or prospectiveSmaller number of patients than more powerful case-control or RCTs

Case SeriesProvide information when other types cannot

or should not be undertakenCase 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 ST-segment elevation myocardial infarction

Introduction to Article

Electrocardiographic ST-segment elevation: Takotsubo cardiomyopathy versus STEMI

AMERICAN JOURNAL OF EMERGENCY MEDICINE, 2009

What is Takotsubo cardiomyopathy?Also known as left ventricular apical

ballooning syndrome, ampulla CM, stress CMDevelop anginal symptoms and CHF in times

of stressExtreme: acute pulmonary edema,

cardiogenic shock

EKG & LabsST segment and/or T wave abnormalitiesSimilar to what’s seen in STEMISerum markers may be elevated

Cath & ventriculogramCatheterization: abnormal LV function, but

NORMAL coronary arteries

Diastole Systole

Diagnostic criteria (Mayo)1) transient LV apical akinesis or dyskinesis2) absence of obstructive CAD3) new EKG abnormalities in absence of

concurrent conditions

Discussion of this Case Series

How Patients Were SelectedReviewed 12 consecutive cases of Takotsubo

CM that presented to UVA3 case excluded because of incomplete dataThen took 9 consecutive cases of STEMI for

comparison18 cases total (9 TCM, 9 STEMI)—same time

periodComparisons made between 2 groups

Demographic ResultsDescriptor 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 ComparisonsEKG abnormality Takotsubo STEMI

ST-segment elevation 66.7% 100%

Inferior 0 55.6

Lateral 11.1 33.3

Anterior 55.6 33.3

ST-segment depression

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

Other comparisonsCXR findings were similar in both groupsInitial troponin elevation similarSTEMI peak troponin 7.34 vs TCM with 4.91EF on echo—32.7% in Takotsubo, vs 25.2% in

STEMI

Discussion of Article

DesignNot 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.

StrengthsUsed 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

WeaknessesTime 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

Weaknesses3 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.

ConclusionsTakotsubo CM often mimics ACSAnginal chest pain with acute heart failureThis retrospective case series shows its

difficult to distinguish the 2 in the ER

Take Home MessagePhysicians need to be aware of this

alternative diagnosis to a STEMIStill need to watch for dysrhythmias &

cardiogenic shock withIdeally, if Takotsubo CM suspectedcardiac

catheterization should be chosen over fibrinolytics

Further DiscussionDr. Hunter Young, former Barker ACS