New developments in cardiology

The annual European Society of Cardiology (ESC) Congress played host to around 28,000 delegates from 140 countries this year, who came to hear about the latest research in the field of cardiology. Of great interest to many delegates were the results of the IABP-SHOCK II study, which showed that the Intraaortic balloon pump (IABP) does not improve mortality rate in cardiogenic shock patients. An IABP inserted in the aorta is currently the most widely used support device in the treatment of cardiogenic shock. However, there is still only limited evidence that it is actually beneficial for the patient. Only a few registry studies and clinical trials have shown that its use can improve blood pressure and the perfusion of the coronary arteries. Based on these existing studies, international guidelines recommend the use of an IABP in patients with cardiogenic shock. However, because of the lack of evidence of its efficacy, an IABP is currently only used in 25%-40% of shock patients. The IABP-SHOCK II trial was designed to look at whether an IABP can improve mortality if used in conjunction with optimal medical therapy and early reopening of the infarct-related artery. Approximately 5%-10% of patients after a heart attack experience the complication of cardiogenic shock, which results from an inability of the heart to meet the body’s demand for oxygen. In Europe around 70,000 patients are diagnosed with cardiogenic shock each year. In the past decade mortality related to cardiogenic shock has been reduced, mainly by early reopening of the infarct-affected artery by early balloon inflation. However, the mortality rate in these patients is still extremely high, with approximately 50% dying within the first 30 days. The IABP-SHOCK II trial randomised 600 patients enrolled in 37 centres in Germany to either an IABP or conventional optimal medical treatment alone. The hypothesis tested was that the IABP could reduce the rate of mortality within 30 days. However, the study found no reduction in 30-day mortality rate in the IABP group when compared to the control group having standard care alone. The primary results are shown in Figure 1, with no effect over time between the two study groups. Several subgroups were also evaluated and here too no clear benefit for the IABP was found. Similarly, the IABP showed no improvement in blood pressure, no reduction in treatment time in the intensive care unit, no decrease in the duration or dose of drugs prescribed, and no improvement in organ perfusion. However, the trial results did show that the IABP did not induce complications, and was shown to be a safe device. Presenting the trial results at Congress, Professor Holger Thiele from the University of Leipzig Heart Centre in Germany said: “This large multicentre trial was unable to show a benefit for the currently most widely used mechanical support device in cardiogenic shock.”

TAVI

TAVI was also a hot topic at the event. Transcatheter aortic valve implantation (TAVI) is a new technique leading to meaningful and sustained improvements in health-related quality of life in patients with severe aortic stenosis. According to a study presented at congress by Professor Till Neumann, these improvements are maintained for at least one year. Aortic stenosis is a common valvular heart disease with increasing incidence, which is believed to relate to the ageing population. Today, the prevalence of aortic stenosis is estimated at about 2.5% of 75 year olds and 8.1% of people aged 85 years. TAVI has been shown to improve survival, compared with standard therapy in patients with severe aortic stenosis who cannot have surgery. For older patients, in particular, with aortic stenosis conventional surgical aortic valve replacement cannot always be offered. As a consequence, around 30% of these patients currently do not undergo an operation. TAVI offers an alternative treatment option for these patients. The prospective multicentre German transcatheter aortic valve interventions registry dates from January 2009 and includes patients with symptomatic, severe aortic stenosis. Prof. Neumann explained further: “The registry was designed to monitor current use and outcome of transcatheter aortic valve interventions, including TAVI, in daily clinical routine, and to evaluate safety, effectiveness and health economic data, giving an insight into a real world setting of using the TAVI procedure.” Health-related quality of life was assessed at baseline, at 30 days and 12 months with the EQ-5D questionnaire, a prominent instrument to measure health-related quality of life. The study used quality of life data for a total of 415 patients who survived 12 months after TAVI (average age 81.9 ± 5.9 years; men 37.3%). At 12 months, TAVI patients reported improvements with regard to each single dimension of the EQ-5D. In particular the distribution of the three levels (no problems, some problems, extreme problems) changed with regard to usual activities (Fig. 2) and discomfort (Fig. 3) after 12 months. For usual activities, the proportion of patients with no problems rose from 17.5% to 48.6%, with some problems decreased from 72.5% to 39.7%, and with extreme problems increased slightly from 10.1% to 11.7%. For discomfort, the proportion of patients with no problems rose from 22.7% to 61.9%, with some problems decreased from 69.1% to 33.3%, and with extreme problems decreased from 8.3% to 4.8%. Prof. Neumann said: “Patients gain improvements in their usual activities and feel more comfortable. One of the main findings of the study is an increase in patients’ self-ratings of quality of life after TAVI.” Scores on the visual analogue health scale (EQ VAS), which records the patient’s self-rated health on a vertical, visual analogue scale, significantly improved from a mean value of 44.7% ± 16.5 at baseline to 62.9% ± 17.4 at 30 days. However, an even more important consideration was the fact that this benefit in quality of life was sustained. “The results of the study demonstrate that this minimally invasive procedure not only saves lives but also leads to a remarkable improvement in healthrelated quality of life in a real world setting,” concluded Prof. Neumann. “This benefit in quality of life lasts for a long time period. Patients with severe aortic stenosis can profit from TAVI – the gain in health-related quality of life confirms this. Our findings regarding quality of life could give further impetus to the argument for performing TAVI in older patients with severe aortic stenosis.”