Adecade of cardiothoracic surgery at a tertiary care hospital in Karachi, Pakistan
Fahad Javaid Siddiqui, Shahid Ahmed Sami
Department of Surgery, Aga Khan University, Karachi, Pakistan.
Objective: The medical records at Aga Khan University were reviewed to analyze the trends, mortality and
patients characteristics of cardiothoracic surgeries in the last decade.
Method: The medical records of all adult cardiac, thoracic and combined cardiothoracic operations performed
during January 1995 to December 2004 at the Aga Khan University Hospital were reviewed. Data were retrieved
and analyzed for trends, patient characteristics, and procedure mortality.
Results: From January 1995 - December 2004, 4553 cases were eligible for the study, of which 73% were males
and 9.4% were children. Male to female ratio changed from 1.3:1 to 3:1 from childhood to adulthood. Number of
patients requiring cardiothoracic intervention increased continuously throughout the period, cardiac operations
outnumbering thoracic or combined procedures. Ten-year average annual mortality remained 4.8% with slight
variation per annum. Age distribution of cardiac surgery patients remained the same, however, constantly
increasing number of over-70-year olds was observed. Mortality for isolated CABG, isolated valve and CABG
with valve remained 1.9%, 4.3% and 18.3% respectively.
Conclusion: Trends of cardiothoracic procedures appear similar to those in the developed countries, so are the
mortality figures (JPMA 57:532:2007).
With the increase in chronic non-communicable and
man-made disorders, incidence of cardiac and thoracic
diseases has increased throughout the world with
concomitant rise in interventions required to treat these
diseases.1,2This increase is also due to the greater
acceptability of the treatment modalities as quantum leaps
in the progress of technology have made interventions
easier and safer.3-8This control over the situation is gained
because hospitals providing such services in the
industrialized world have developed a mechanism to share
their experience, and disseminate the knowledge to the
scientific community and medical industry across the
globe.9,10 This mechanism has allowed continuous
monitoring of effects of different procedures, techniques
and implants on the outcomes, thus providing a useful
feedback for making appropriate adjustments and
refinements in all aspects of cardiothoracic surgery.
In this background of ever increasing success rate, it
is not surprising that cardiac and thoracic surgeries are now
a commonplace in medical practice. Number of Coronary
Artery Bypass Grafting (CABG) alone exceeds 800,000 per
year globally.11Thoracic as well as the congenital cardiac
operations are also being performed with increasing
frequency and improved results.
Sharp increase in the chronic non-communicable
diseases such as coronary heart diseases (CHD) in
developing countries has also compelled the healthcare
sector to provide advanced surgical services in this part of
the world, but the concomitant development of data
collection and sharing mechanism is largely lacking,
especially in Southeast Asian region.1Consequently there is
paucity of scientifically collected data to show the need,
benefits and effects of interventions for CHD. A major
deterrent to maintain a data collection and processing
system (database) is its considerable cost, however, its
benefits outweigh the cost.12
At the Aga Khan University, a private tertiary care
hospital, with state of the art facilities for cardiothoracic
support, we had the opportunity to retrieve the data of last
10 years. The objective of this medical record review was to
look at the trends of cardiac, thoracic and combined
surgeries, patient characteristics and their outcomes over
the last decade.
A medical record review of all patients admitted to
AKUH for cardiothoracic surgery during last 10 years was
conducted. For administrative purposes some variables are
recorded in our hospital's database routinely, hence we
could obtain secondary data for the analysis. From the
AKUH information system department database we
retrieved data with selection criteria of 'all the surgeries,
done by classified cardiothoracic surgeons from January
1995 to December 2004'. All operating room (OR) re-visits,
e.g. for re-opening due to complications were excluded.
532 J Pak Med Assoc
Age was noted as the completed years at the time of
surgery. Any patient who had not crossed his/her 14th
birthday on the day of surgery was considered as a child.
Surgical procedures were coded using ICD 9.0
(International Classification of Diseases 9.0 Clinical
Modification). Any procedure having a code from 35.00 to
39.99 was considered as 'cardiac procedure', whereas all
procedures given codes from 30.00 to 34.99 were
considered as 'thoracic procedure'. All procedure codes
outside this range were for adjuvant procedures hence did
not affect the original classification of a case. However, if a
patient underwent procedures from both the cardiac and
thoracic code ranges, it was considered as 'cardiothoracic
procedure'. Multiple procedures done in one OR visit were
represented once. Isolated CABG operation was defined as
CABG with no simultaneous procedure involving valves,
aneurysms, septa, pericardium or any procedure for
congenital malformation. Isolated valve cases were also
defined in the same way. Any death before discharge of the
patient was counted towards mortality due to the surgery. As
cardiac procedures were the most common type of
procedures, it was analyzed in greater detail.
Data was retrieved from AKUH electronic database
and imported into SPSS® version 12.0 (SPSS Inc., Illinois,
USA). All reopen procedures were deleted from the dataset.
Appropriate variables were created using ICD (9.0 CM)
procedure codes. Frequencies and cross tabs were run to get
statistics. Charts were made by exporting tables to MS
Excel® (Microsoft Corp. Redmond, WA, USA).
From January 1995 to December 2004, we found
cases of cardiothoracic
inclusion/exclusion criteria. Out of these 3321 (72.9%)
were males. Adults were 4217 (90.6%). Among adults, male
to female ratio was 3:1 whereas among children it was
1.3:1. Majority of the procedures were cardiac (75%),
cardiothoracic procedures were 5% and rest were thoracic
(20%). Trend over time showed ever increasing number of
cardiac operations, whereas number of other procedures
displayed relatively little change (Table 1). Cardiac
procedures were more commonly done on very young,
middle and old age people whereas thoracic procedures
were mostly done on people between 15 to 30 years of age
(Figure 1). As the age increased, the percentage of females
undergoing cardiac or thoracic surgery decreased from
nearly 46% to 20% stabilizing there after (Figure 2).
4553 surgery fulfilling
Overall ten year in-hospital mortality of the cardiac
surgery unit remained 4.8%, 8 (0.2%) patients either left
against medical advice or were transferred to another
facility for various reasons and the rest (95.0%) were
discharged home. Combined mortality trend over the
decade showed that there was a little variation, ranging from
2% to 10%. Category wise ten year mortality of cardiac,
thoracic and combined procedures was 3.4%, 5.4% and
Table1. Cardiothoracic procedures and proportionate composition of
work load at cardiothoracic surgery department, the Aga Khan
University, Karachi, Pakistan (1995 - 2004).
Type of operations
Cardiac (%)Thoracic (%) Cardiothoracic (%)
1 09 (16.5)
Figures 1. Age distribution of cardiothoracic surgical procedures done at the Aga Khan
University Hospital, Karachi, Pakistan (1994 - 2004).
Figures 2. Gender distribution of cardiothoracic procedures done at the Aga Khan University,
Karachi, Pakistan (1995 - 2004).
Vol. 57, No. 11, November 2007 533
23.1% respectively whereas mean (SD) of these mortalities
were 4.4 (1.3), 6.1(2.0) and 22.2 (22.2) respectively. There
was also no significant difference of average mortality of
these categories between first half of the decade and the
second (p-values: 0.63, 0.73 & 0.98).
Age distribution of patients undergoing cardiac
surgical procedures did not show any change although we
received larger number of patients from each group in
successive years. Patients undergoing cardiac surgery in
their 70s increased constantly and in 2004 we also operated
upon 3 patients who were in their 8th decade of life.
Isolated CABG was the most commonly done
operation among the cardiac procedures (2674; 79%)
followed by isolated valve operations (255; 7%). Other
major cardiac procedures (213; 6%) included surgery of
aneurysms, septal repairs, pericardiectomy, correction of
Tetralogy of Fallot, and systemic to pulmonary shunts.
CABG with valve or other procedures were relatively less
frequently done (67; 2%). Remaining were miscellaneous
procedures like redo CABG, redo valves, redo CABG with
valve and cardiac myxomas (208; 6%).
Ten year mortality of isolated CABG and isolated
valve was 1.9% and 4.3% respectively. CABG when
combined with valve or any other procedure carried higher
mortality (18.3% and 14.3%). Other major and
miscellaneous cardiac procedures (as described above) had
8.5 and 10.6% mortality.
Isolated CABG mortality is now considered as the
indicator of quality of care of any cardiac surgery unit. Our
experience showed that initially mortality increased as the
patient load increased until 2001 but thereafter it constantly
decreased to reach a lowest level of 1.1% in 2004.
We also looked at the isolated valve mortality. At our
unit total of 255 isolated valve procedures were done from
1995 to 2004. Out of these less than one fourth (59) were
carried out in first half. Total deaths were 11 making over all
mortality of 4.3%. Mean (SD) of mortality per year was
4.5% (4.1). There was no association between year of
surgery and mortality (p<0.18). Average mortality rate
during the first half was also compared with the second half
using t-test. No significant difference was found again
(p<0.96). Mortality nevertheless ranged from 0 - 12%.
Despite being fortunate to have the facilities of a
well established information technology department which
keeps electronic records of all the procedures being done at
the hospital, only a very small number of variables were
being recorded. It is because this data was not collected for
medical outcome research purposes, but rather for
administrative purposes. Therefore, we had secondary data
with its inherent problems, including missing information
and unclear definitions. Data were also not entered twice to
enable detection of key punching errors. However, during
our analysis we found only couple of key punching errors
which was rather unusual for any secondary data. Further,
as for the coding of surgical procedures ICD codes were
used, ambiguity in definitions was also avoided. So we had
relatively much valid data to analyze.
Population is aging world over and so is in our
region. Demographic and epidemiologic transitions are
behind this phenomenon.1In Europe life expectancy was
raised from 71 years to 83 years in the last four decades and
life expectancy at age 65 ranged from 16 to 19 years.13In
US it increased to around 2 years since 1989, the smaller
increment may be due to already high life expectancy of
75.5 years.14A much sharper 5-6 year increase has been
observed in Southeast Asia in the last 7 to 8 years.15On the
one hand, it is a sign of protection from diseases and
hazards in early years of life but paradoxically, it also serves
as an indicator of higher prevalence of degenerative
diseases in later age.16Increasing incidence of condition
like coronary artery disease with increasing age has been
reported in the absence of any other risk factor.17,18This
provides sufficient evidence to support our observation that
more and more people are requiring intervention for
cardiovascular illnesses. Furthermore, diabetes mellitus, an
established risk factor for coronary heart disease (CHD) is
on the rise worldwide, while obesity, smoking,
dyslipidemias and hypertension are highly prevalent
indicating that CHD will rise further.19-21Moreover, despite
addition of other cardiothoracic surgery centers in the city
AKUH received increasing number of patients. This gives
further support to our premise that number of people
requiring cardiovascular interventions is rising.
We found that as the age increased, males made the
larger proportion of the cardiothoracic surgery patients. In
the early years of life, the male to female ratio was almost
equal. This is because gender does not significantly
influence the occurrence of congenital malformation,
therefore both sexes were represented equally. However, we
know that as age increases, certain factors act differently on
each gender for example females are protected by their
hormones against cardiovascular diseases.9However, this
change in proportion might not be only due to physiological
reasons. Factors like health care behaviour may also be
acting, at least in our part of the world, e.g. preference is
given to the bread earner of the family in case of health care
need. This preference often persists even after the bread-
earner has grown old and has retired.22
Isolated CABG mortality world wide is decreasing.
The European Association of Cardio-thoracic Surgery
534 J Pak Med Assoc
database report of 2005 shows the same trend and so does Download full-text
the Spring report of Society of Thoracic Surgeons, USA.10
Furthermore, isolated CABG is now considered to be the
indicator for quality of care of any unit as the procedure is
now standardized and statistical models have been
developed to calculate the preoperative mortality of each
patient undergoing isolated CABG.
Valve surgery is although being done more
frequently, but not only is the mortality still high, around 4
- 6%, but also no clear decreasing trend is seen.10Our
experience, too, was not much different from the other
centers across the globe. It ranged from 0% to 12% over the
decade in our center with a decline in later years.
Despite having good quality data, we felt restricted
due to the paucity of variables available to us. This is
because there is no mechanism for collecting and
computerizing cardiothoracic surgery patient data routinely.
Variables to look at the preoperative mortality of patients
were insufficient to adjust mortality rate. The high mortality
of cardiac surgery can be due to selection of high risk cases
for surgery and may not always indicate poor quality of
care. The evaluation of such patients with risk stratification
systems like EuroSCORE, Parsonet score etc have helped in
calculating risk adjusted mortality which is gradually
becoming a prime indicator of performance.
Since we are presenting data of a single center only,
it is not representative of the population. Therefore, there is
a dire need to develop and maintain data collection and
processing systems for cardiothoracic surgeries at all the
centers providing such services. This can help formulate
national policies for the future.23
Cardiac and thoracic operations are being done more
frequently in which cardiac procedures dominate. Less than
10-year-olds and adults over 40 undergo cardiac surgery
more frequently. Thoracic surgery is more commonly done
in age group of 10 - 40 years. Percentage of females among
cardiothoracic surgery patients decreases as the age
increases which may not only due to physiological reasons.
The cardiac surgery trends show increasing number of
elderly being offered surgery. Most common procedure is
isolated CABG with a crude mortality not different from
western centers. Other isolated and combined procedures
carry higher mortality risk.
Trends of cardiothoracic surgery seem comparable
with the west but extensive and more representative data
must be obtained from centers across the country to identify
national trends in cardiothoracic surgery ultimately leading
to development of firmly based action plan.
We hereby acknowledge the support of Health
Information Management Systems, The Aga Khan
University, especially the help of Ms. Amna Safdar, who
provided us the required data for analysis. There is no
conflict of interest to declare.
1. Omran AR. The epidemiologic transition. A theory of the epidemiology of
population change. Milbank Mem Fund Q 1971;49:509-38.
2.Murray CJL, Lopez AD. Mortality by cause for eight regions of the world:
Global Burden of Disease Study. Lancet 1997;349:1269-76.
3.Treasure T. Advances in cardiac surgery. Practitioner 2001;245:422-4, 426,
4.Wiegand DL. Advances in cardiac surgery: valve repair. Crit Care Nurse
5.Mark JB. Advances in General Thoracic Surgery: Introduction. World J Surg.
6.Karl TR, Cochrane AD, Brizard CP. Advances in pediatric cardiac surgery.
Curr Opin Pediatr. 1999;11:419-24.
7. Ogella DA. Advances in perfusion technology--an overview. J Indian Med
Assoc. 1999;97:436-7, 441.
8. Edmunds LH Jr. Advances in the heart-lung machine after John and Mary
Gibbon. Ann Thorac Surg. 2003;76:S2220-3.
9. Keogh BE, Kinsman R. Second European Adult Cardiac Surgical Database
Report 2005. Berkshire (UK): The European Association for Cardio-thoracic
Surgery; 2005 Sept. ISBN 1-903968-13-5
10. Society of Thoracic Surgeons. Executive summary STS Spring 2005 2005
[online][cited 2007 July 31]. Available from URL: http://www.sts.org/
documents/pdf/Spring2005STS-ExecutiveSummary.pdf. Accessed on 31,
11. Yusuf S, Zucker D, Peduzzi P, Fisher LD, Takaro T, Kennedy JW et al. Effect
of coronary artery bypass graft surgery on survival: overview of 10 year
results from randomized trial by the Coronary Artery Bypass Graft Trialists
Collaboration. Lancet 1994;344:563-70
12.Siddiqui FJ, Sami SA. Maintaining health information system at healthcare
institutions: a need of the day. J Pak Med Assoc. 2005;55:465.
13.EUROSTAT. Population statistics: Theme 3 - Population and social
conditions. p. 87. http://epp.eurostat.ec.europa.eu/cache/ITY_OFFPUB/KS-
BP-04-001/EN/KS-BP-04-001-EN.PDF Accessed July 31, 2007
14.US Census Bureau. Expectation of Life at Birth, 1960 to 2004, and
Projections, 2010 and 2015 [online][cited 2007 July 18]. Available from URL:
http://www.census.gov/compendia/statab/tables/07s0098.xls. Accessed on 31,
15.CIAWorld Fact Book. [homepage of Countries of the World][online available
from URL: http://www.theodora.com/wfb/. Accessed on 31, July 2007.
16.Rajput MA. Health of elderly: global and national perspectives. J Pakistan Inst
Med Sci 2004;15:893-5.
17.Menotti A, Lanti M. Coronary risk factors predicting early and late coronary
deaths. Heart 2003;89:19-24.
18.Menotti A, Lanti M, Puddu PE, Kromhout D. Coronary heart disease incidence
in northern and southern European populations: a reanalysis of the seven
countries study for a European coronary risk chart Heart 2000;84:238-44.
19.WHO. Atlas of heart disease and stroke. Part II: Risk factors [online][cited
2001 July 31]. Available from URL: http://whqlibdoc.who.int/
publications/2004/9241562768_p3.pdf. Accessed on 31, July 2007.
20.King H, Aubert RE, Herman WH. Global burden of diabetes, 1995-2025.
prevalence, numerical estimates, and projections. Diabetes care
21.WHO. Tobacco control database. Prevalence of smoking among adults in
European countries [online] 2006 April 01 Last Update [cited 2007 July 31].
Available from URL: http://data.euro.who.int/tobacco/Default.aspx?
TabID=2444. Accessed on 31, July 2007.
22.Agha SA. Gender issue neglected aspect of health promotion in Pakistan J Pak
Med Assoc 1999;49:309-11.
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