The decline of coronary heart disease mortality in the United States and Western Europe is one of the great accomplishments of modern public health and medicine. Cardiologists and cardiovascular epidemiologists have devoted significant effort to disease surveillance and epidemiological modeling to understand its causes. One unanticipated outcome of these efforts has been the detection of early warnings that the decline had slowed, plateaued, or even reversed. These subtle signs have been interpreted as evidence of an impending public health catastrophe. This article traces the history of research on coronary heart disease decline and resurgence and situates it in broader narratives of public health catastrophism. Juxtaposing the coronary heart disease literature alongside the narratives of emerging and reemerging infectious disease helps to identify patterns in how public health researchers create data and craft them into powerful narratives of progress or pessimism. These narratives, in turn, shape public health policy.