Clinical characteristics of patients with heart failure and preserved left ventricular systolic function : a descriptive cohort study and comparison with heart failure and reduced systolic function
At the time of starting this work, the syndrome of heart failure with preserved systolic function was a neglected area in clinical cardiovascular research. The aim of this study was to improve our understanding of this condition by investigating the prevalence of HF-PSF in a cohort of patients admitted to hospital with heart failure, examining their clinical characteristics and determining their prognosis. By comparing the detailed clinical characteristics of patients with HF-PSF to those of patients with reduced systolic function, this study has provided a number of important insights into this common syndrome. Patients with preserved systolic function heart failure tend to be older, and are more likely to have a history of hypertension. These findings have now become well established in the HF-PSF literature. In relation to comorbidity, I specifically examined the prevalence of chronic obstructive pulmonary disease (COPD) in the subset of my study patients with HF-PSF, with a view to determining if they may have been misdiagnosed. On the contrary, while few patients had both a normal BNP and abnormal PFTs, a significant number of those patients with HF-PSF who had previously received a clinical diagnosis of COPD, actually had normal spirometry but an elevated BNP. This rather suggests that they may have been misdiagnosed with COPD, when in fact, they were suffering from HF-PSF. The importance of the interplay between COPD and HF is increasingly recognised, and these results serve to underline the need for further study in this area. In addition to the idea that HF-PSF was merely misdiagnosis, until recently conventional expectations were that HF-PSF would produce a mild version of the clinical syndrome. However, in this study I found that patients with HF-PSF did indeed display markers of severe and complicated heart failure. The majority were classified as Killip IIA or greater on admission to hospital, and the majority had moderate renal dysfunction. This suggestion that HF-PSF is not a benign condition is borne out by the mortality data from this study. All-cause mortality in the HF-PSF group, although lower than that for heart failure with reduced systolic function, was significant, with a case fatality rate of 37% after three years. This high mortality rate underscores the need for effective treatments for patients with HF-PSF.