Background:  Elderly represent the fastest growing portion of cardiovascular patients (1).Shock index (SI) is the ratio of heart rate (HR) and systolic blood pressure (SBP). Although SI have been used initially to evaluate the hemorrhage and acute circulatory failure (2), studies have demonstrated that SI is a useful predictor of short and long term mortality in patients with STEMI(3-6).

               We aimed to test the validity of cardiac index in predicting cardiogenic shock and in hospital mortality in patients 90 years or more who underwent coronary angiography ± intervention.

Methods:  We retrospectively studied 108 (0.25% of 43385) consecutive patients ≥ 90 years undergoing cardiac catheterization ± intervention in Zentralklinik Bad Berka in the period between 2003 and 2014.

34.6% of patient had 3 vessels disease. Left anterior descending artery (LAD) was the most affected coronary artery (67.6%). 56.5% were managed with percutanous coronary intervention (PCI).

                The incidence of shock in our cohort was 17 patients (15.7%). The majority 15/17 (88.2%) were cardiogenic due to pump failure, 1/17 (5.9%) was due to ventricular septal defect due to myocardial infarction. 1/17 (5.9%) had septic shock with cardiac failure contribution.

The mortality rate was 15.7% (17 patients out of 108). Of these, nine (52.9%) Patients died due to cardiogenic shock as a result of pump failure. The mortality in nonagenarians in cardiogenic shock was 9/15 (60%). One patient (5.9%) died due to cardiogenic shock due to VSD. 

There was no statistically difference between the groups regarding basic characteristics.

Table 1 show the difference of systolic, diastolic and mean blood pressure as well as the heart rate between the group with shock (group 1, 17 Patients) and the group without shock (group 2, 91 patients) using Mann-Whitney test.

Using the Receiver Operating Characteristic (ROC) curve analysis, we have found that Shock Index more than 0.61 can predict shock with a sensitivity of 100% and specificity of 64% (figure1) and in hospital mortality with a sensitivity of 77% and sensitivity of 61.2%.  

Using a cut off value of more than 0.82, SI could predict a cardiogenic shock with a sensitivity of 58.3% and specificity of 90.7% and in hospital mortality with a sensitivity of 53.8% and sensitivity of 90.6% (figure 2). 

Conclusion:  shock index could be a prognostic predictive parameter to detect cardiogenic shock and in hospital mortality in nonagenarian undergone coronary angiography ± intervention and therefore could be used to early detect those high risk patients for shock and death . 

Referrences:

     1- Gayed et al:Clinical presentation, comorbidities and complications in nonagenarians undergoing coronary angiography and Intervention, tertiary center analysis. Int Heart J 2017;85:180184.

2.       2- Rady MY et al: Shock index: a re-evaluation in acute circulatory failure. Resuscitation 1992;23 3:227-234.

3.       3- Bilkova D et al: Shock index: a simple clinical parameter for quick mortality risk assessment in acute myocardial infarction. Can J Cardiol 2011;27 6:739–742.

6.